Changeset 0.23.2 (#155)

2026-03-06 23:17:03 +00:00
parent 4c6555cb06
commit 2dc4514a57
36 changed files with 2784 additions and 192 deletions
--- a/2
+++ b/2
@@ -1 +1 @@
-0.23.1
+0.23.2
--- a/docs/TODO-0.23.2.md
+++ b/docs/TODO-0.23.2.md
@@ -0,0 +1,399 @@
+# TODO — v0.23.2
+
+Working checklist. Covers remaining v0.23.1 multi-user scope plus
+deferred v0.22.8 surface integration and the channel persistence bug.
+ROADMAP and CHANGELOG updated when work is complete.
+
+---
+
+## Already Shipped (in 0.23.0 / 0.23.1 changesets)
+
+Backend foundation is in place. These are done and should not be
+re-implemented.
+
+- [x] Migration 016: `ai_mode`, `topic` on channels; `user_presence`
+      table; channel type constraint extended to `dm`, `channel`
+- [x] `ai_mode` guard in `completion.go` — `off` returns 403,
+      `mention_only` without @mention returns `{status: delivered}`
+- [x] `resolveMention()` resolves users (steps 3–4: exact + prefix
+      on `users.username`, self-mention blocked)
+- [x] User @mention in completion handler — skips AI, attempts
+      `NotifyUserMention` via interface cast (hub method not yet
+      implemented — silently no-ops)
+- [x] Presence endpoints: `POST /presence/heartbeat` (upsert),
+      `GET /presence?users=...` (90s threshold query)
+- [x] Folders: full CRUD handler (`handlers/folders.go`), wired routes
+- [x] `CreateChannel` accepts `type` field (default `direct`)
+- [x] `ListChannels` supports `?types=dm,channel` multi-filter
+- [x] Three-section sidebar in `chat.html` (Projects / Channels / Chats)
+- [x] `renderChannelsSection()` in `ui-core.js` (# / person icons,
+      unread badges, online dots, active state)
+- [x] `selectChannel()`, `newChannelOrDM()`, `loadChannels()` in
+      `projects-ui.js`
+- [x] Folder UI: create, rename, delete, context menu, drag chats
+- [x] Chat list filters out `type=channel` and `type=dm`
+- [x] API methods: `createChannel(title,model,sp,type)`,
+      `listSidebarChannels()`, `presenceHeartbeat()`
+- [x] `persona_groups` + `persona_group_members` tables (migration 004)
+- [x] `PersonaGroup` / `PersonaGroupMember` model structs
+- [x] Channel participants: CRUD handler, auto-created on channel create
+
+---
+
+## Bug Fixes
+
+- [x] **Channel persistence through refresh.** `loadChannels()` read
+      `resp.channels` but `ListChannels` returns a `paginatedResponse`
+      with `data` key. Channels created in-session appeared (pushed to
+      `App.channels` client-side) but vanished on reload because the
+      API response was always parsed as empty.
+      Fix: `resp.channels` → `resp.data` in `projects-ui.js`.
+
+- [x] **Folder drag-and-drop completely broken.** Three compounding
+      issues:
+      (a) `loadChats()` never mapped `c.folder` → `folderId` — all
+          chats rendered as unfiled regardless of DB state.
+      (b) Folder groups rendered "Drop chats here" but had zero drag
+          event handlers (`ondragover`/`ondrop` missing).
+      (c) No drop zone existed for unfiling a chat or removing from
+          a project — the Chats section body had no drag handlers.
+      Fixes: added `folderId: c.folder || null` to `loadChats()` map;
+      added `ondragover`/`ondragleave`/`ondrop` to `.sb-folder-group`
+      divs in `renderChatList()`; added `onChatSectionDrop` handler to
+      `#sbBodyChats` (handles both unfile-from-folder and remove-from-
+      project); added `onFolderDrop` and `moveChatToFolder` functions;
+      added "Move to folder" / "Remove from folder" to chat context
+      menu; added drag-over CSS for folders and section body.
+
+- [x] **DM creation 404 on `/api/v1/users`.** Route didn't exist.
+      Added `GET /api/v1/users/search?q=` endpoint returning id,
+      username, display_name for approved users (max 20, excludes
+      caller). Registered on `protected` group (any authed user).
+      Rewrote DM creation UI from text input to lazy search modal —
+      shows all users on open, filters as you type with 200ms debounce,
+      click to select and create DM.
+
+- [x] **No unfiled drop zone when folders exist.** When folders were
+      present, folder groups consumed all space in `#sbBodyChats`,
+      leaving no bare target to drag a chat out of a folder. Added
+      `.sb-unfiled-zone` wrapper around unfiled chats with its own
+      drag handlers. Shows "Drop here to unfile" hint when zone is
+      empty. `onUnfiledDrop` handles both unfile-from-folder and
+      remove-from-project.
+
+- [x] **No channel CRUD.** Channel sidebar items had no context menu
+      or management affordances. Added: right-click context menu with
+      Rename / Set topic (channels only) / Delete. Inline ✕ delete
+      button on hover (same pattern as chat items). `renameChannel()`
+      uses `_showCreationDialog` with pre-filled value. `deleteChannel()`
+      with confirm dialog removes from `App.channels` + `App.chats`,
+      clears active if deleted channel was selected.
+
+- [x] **Drag-over highlight persists.** `onChatDragEnd` only cleared
+      `.project-group.drag-over` — missed folders, unfiled zone, and
+      section body. Fixed to `document.querySelectorAll('.drag-over')`
+      so all drop targets are cleaned up when a drag ends anywhere.
+
+- [x] **Channel ⋯ menu inconsistency.** Channels used ✕ delete button
+      + right-click only, while folders used ⋯ hover button. Replaced
+      channel ✕ with `.sb-ch-menu` ⋯ button matching the folder
+      pattern (hidden, shown on hover, triggers context menu on click).
+      Both channels and folders now have ⋯ hover + right-click.
+
+- [x] **Folder delete silently spills chats.** `deleteFolder()` always
+      unfiled contained chats with no user input. Replaced with a
+      three-button modal when the folder has chats: "Keep chats"
+      (unfile and preserve), "Delete chats too" (hard-delete all
+      contained chats), or Cancel. Empty folders get a simple confirm.
+      Delete-all path iterates chats, calls `API.deleteChannel()` for
+      each, clears active state if needed, then removes the folder.
+
+- [x] **Folder ⋯ button shifts collapse arrow.** The ⋯ button used
+      `display:none/block` which caused reflow on hover, shifting the
+      arrow left. Fixed: swapped DOM order (⋯ before arrow), changed
+      to `visibility:hidden/visible` so space is always reserved.
+      Applied same fix to channel ⋯ button. Arrow gets fixed width
+      with `flex-shrink:0`.
+
+- [x] **Channels STILL not surviving refresh (round 2).** The unread
+      count subquery in `ListChannels` referenced
+      `cp.last_read_message_id` — a column added by migration 017.
+      If 017 hasn't been applied (fresh DB only has through 016), the
+      query fails and returns zero channels. Additionally, the `$1`
+      parameter was reused in Postgres (subquery + WHERE) which would
+      break SQLite's positional `?` binding.
+      Fix: rewrote unread subquery to use `last_read_at` (exists since
+      migration 005). Split `$1` reuse into `$1` (subquery) and `$2`
+      (WHERE), with `args` providing `userID` twice. `MarkRead` also
+      fixed to use `last_read_at` as primary, `last_read_message_id`
+      as best-effort (silently fails if 017 not applied).
+
+- [x] **Settings Models section empty.** Template `models` section
+      fell through to the generic `settingsDynamic` div, but
+      `loadUserModels()` wrote to `#userModelList` which didn't exist.
+      Added dedicated template sections for `models` and `teams`.
+
+- [x] **CI: TestIntegration_Messages_CRUD 500.** `ListMessages` JOIN
+      used `u.avatar` but the column is `avatar_url` in the users
+      table. Query failed on SQLite (Postgres would fail too). Same
+      bug in `treepath/path.go` `resolveSenderInfo()`.
+      Fix: `u.avatar` → `u.avatar_url` in both locations.
+
+---
+
+## Design Decisions (resolved)
+
+**Unified active conversation.** `App.currentChatId` and
+`App.currentChannelId` merge into `App.activeConversation = { id, type }`
+where type is `direct|dm|group|channel`. The send path, model bar,
+input state, streaming, session restore, and URL sync all key off
+`activeConversation.id`. The type discriminator drives ai_mode checks,
+context banner visibility, and participant rendering. Refactor touches
+`selectChat()`, `selectChannel()`, `sendMessage()`, session restore in
+`app.js`, and active-highlight in sidebar renderers.
+
+**DM deduplication.** One channel per participant pair. `CreateChannel`
+for `type=dm` checks for an existing DM with the same two participants
+before creating. Display name is the other party's name (from the
+caller's perspective). For future 3+ human DMs: comma-join up to 2
+names + "and N others".
+
+**No LLMs in DMs.** DMs are human-to-human by definition. `ai_mode`
+is `mention_only` — you can @mention a persona for a one-off response,
+but personas are not participants. If you want persistent AI in a
+conversation with another human, that's a Group Chat (`type=group`).
+The taxonomy stays clean.
+
+**Post-creation participant mutation.** Users and personas can be added
+or removed from any channel/group after creation. Participant CRUD
+endpoints already exist. Constraints: DMs cannot drop below 2 human
+participants; groups cannot drop their last persona (becomes a DM at
+that point — block with error, not silent type coercion).
+
+**Channel deletion vs archival.** Governed by `channel_retention.mode`:
+- `flexible` (default): delete or archive freely, user's choice.
+- `retain`: archive only. Delete button becomes "Archive" everywhere.
+  `DELETE /channels/:id` returns 403 for non-admins. Admins purge
+  from the admin panel, subject to retention age floor.
+
+See "Retention Policy" section below for the full lifecycle.
+
+---
+
+## 1 · Unified Active Conversation
+
+Prerequisite refactor. Do this first — everything else builds on it.
+
+- [x] **`App.activeConversation` object.** Replace `App.currentChatId`
+      and `App.currentChannelId` with `App.activeConversation = { id,
+      type }` (null when nothing selected). Update `app-state.js`.
+      Added `activeId` getter, `activeType` getter, `setActive(id,type)`
+      method, and `getActiveChat()` helper.
+- [x] **`selectChat()` migration.** Sets
+      `App.activeConversation = { id: chatId, type: chat.type }`.
+      Session restore reads/writes `cs-active-conversation` (JSON).
+- [x] **`selectChannel()` migration.** Sets
+      `App.activeConversation = { id, type: ch.type }`. Same session
+      storage key. Now also ensures conversation object in `App.chats`
+      for message caching and maps messages into standard shape.
+- [x] **Send path.** `sendMessage()` reads `App.activeId`
+      for the channel ID. No behavior change — the backend already
+      handles all channel types on the same completion endpoint.
+- [x] **Model bar, input state, streaming.** All `currentChatId`
+      references → `App.activeId`. All `App.chats.find(...)` for
+      active chat → `App.getActiveChat()`. 12 files updated.
+- [x] **Sidebar active highlight.** Both `renderChatList()` and
+      `renderChannelsSection()` check `App.activeId` for the
+      active class. Selecting either clears the other.
+- [x] **URL sync.** `history.replaceState` uses
+      `/chat/${activeConversation.id}` regardless of type. The Go
+      route handler already loads any channel by ID.
+- [x] **Session restore.** Reads `cs-active-conversation` JSON,
+      checks both `App.chats` and `App.channels` arrays, calls
+      `selectChat()` or `selectChannel()` as appropriate.
+- [x] **`newChannelOrDM()` integration.** Now pushes to both
+      `App.channels` (sidebar) and `App.chats` (message cache),
+      and sets the new channel as active.
+
+---
+
+## 2 · Channel + DM Plumbing
+
+- [x] **NotifyUserMention on events hub.** Replaced broken gin context
+      interface cast with direct `h.hub.SendToUser()`. Delivers
+      `user.mentioned` event with channel_id, from_user, content
+      preview. Added `user.mentioned` to event route table as
+      `DirToClient`. Added `truncateContent()` helper.
+- [x] **DM creation flow.** Sidebar "+" shows choice dialog (New Channel
+      / New DM). DM flow uses `_showCreationDialog` with username input,
+      looks up user by username, creates `type=dm` channel with
+      `participants: [targetId]`. Sets `ai_mode=mention_only` by default.
+- [x] **DM dedup guard.** `CreateChannel` for `type=dm` queries
+      `channel_participants` for existing DM between the two users.
+      Returns existing channel (200) instead of creating duplicate (201).
+      Self-DM blocked with 400.
+- [x] **Channel context banner.** `#channelContextBanner` div between
+      chat header and messages. `UI.updateContextBanner()` shows/hides
+      based on `App.activeConversation.type`. DM shows partner name +
+      @mention hint. Group shows leader/all routing hint. Channel shows
+      ai_mode + topic. CSS in `chat.css`.
+- [x] **ai_mode and topic in API response.** Added `AiMode` and `Topic`
+      fields to `channelResponse`. `ListChannels` SELECT and Scan
+      updated. `CreateChannel` INSERTs `ai_mode` (defaults to
+      `mention_only` for DMs, `auto` otherwise).
+- [x] **DM participant auto-creation.** `CreateChannel` adds all
+      `req.Participants` as member participants alongside the creator
+      (owner). Works for both Postgres and SQLite.
+- [x] **Unread counts.** Add `last_read_message_id` and `last_read_at`
+      columns to `channel_participants`. Backend computes unread count
+      per channel per user. `listSidebarChannels` response includes
+      `unread_count`. Mark-read on select.
+
+---
+
+## 3 · @mention UX for Users
+
+- [x] **Autocomplete includes users.** `channel-models.js` `onInput()`
+      builds candidates from `App.models` only. Add `App.users` list
+      (fetched once on startup from `GET /api/v1/users` or lightweight
+      endpoint). Merge into candidates with a person icon and different
+      accent color. Resolution order in autocomplete: personas first,
+      then users, then models (mirrors backend `resolveMention`).
+- [x] **User mention pill styling.** `@username` pills render with a
+      different background color (e.g. blue/teal vs persona accent)
+      and person icon to distinguish human from AI mentions.
+- [x] **Notification on mention.** `user.mentioned` WS event handler
+      in `chat.js` increments unread badge on channel sidebar item
+      and shows a toast with content preview.
+
+---
+
+## 4 · Presence
+
+- [x] **Client heartbeat.** 30s `setInterval` calling
+      `API.presenceHeartbeat()`. Start on app init, pause on
+      `visibilitychange` hidden, resume on visible.
+- [x] **Presence on channel load.** When rendering the Channels section,
+      collect DM partner IDs and call `GET /api/v1/presence?users=...`
+      to populate `App.presence`. Wire into `renderChannelsSection()`
+      online dot.
+- [x] **Presence WebSocket events.** Hub broadcasts
+      `presence.changed { userId, status }` to sessions in shared
+      channels. Frontend updates `App.presence` and re-renders the
+      relevant sidebar item (not full re-render).
+
+---
+
+## 5 · Persona Groups + Group Chat
+
+- [x] **Persona group CRUD endpoints.** Wire `persona_groups` and
+      `persona_group_members` to handlers. Routes:
+      `GET/POST /api/v1/persona-groups`,
+      `GET/PUT/DELETE /api/v1/persona-groups/:id`,
+      `POST/DELETE /api/v1/persona-groups/:id/members`.
+      `is_leader` flag on members.
+- [x] **"New Group Chat" flow.** UI in sidebar "+" or separate button.
+      Option A: pick from saved persona group template.
+      Option B: ad-hoc persona picker (checkboxes).
+      Creates `type=group` channel, adds persona participants, sets
+      leader via `is_leader`. Humans and personas can be added
+      post-creation via participant CRUD.
+- [x] **Group leader default response.** In `completion.go`, when
+      channel `type=group` and no @mention in content, resolve the
+      leader persona from `persona_group_members WHERE is_leader`
+      (via `channel_participants` → group membership). Use leader's
+      model/config/system prompt for the completion.
+- [x] **`@all` fan-out.** When `@all` is detected in message content,
+      route to every persona participant. Reuse existing
+      `multiModelStream` path or sequential chain. Depth-1 only
+      (responses from @all do not trigger further chains).
+- [x] **Participant mutation guards.** DMs: block removal if it would
+      drop below 2 human participants. Groups: block removal of last
+      persona (return 400 with clear error message, not silent type
+      coercion).
+
+---
+
+## 6 · Message Attribution
+
+- [x] **Human sender display.** Messages from other human participants
+      show their avatar + display name instead of "You". Requires
+      the message response to include `sender_name`, `sender_avatar`
+      (or `participant_type=user` + `participant_id` that the frontend
+      resolves from a user cache).
+- [x] **Persona sender display.** Already works for streaming via
+      avatar resolution. Verify it works for loaded history in
+      channel context (not just direct chats).
+
+---
+
+## 7 · Channel Lifecycle
+
+- [x] **Archive action.** Context menu on channel/DM sidebar items:
+      "Archive". Sets `is_archived = true, archived_at = NOW()` via
+      `PUT /channels/:id`. Archived channels move to a collapsed
+      "Archived" sub-section at the bottom of the Channels list
+      (or hidden entirely with a "Show archived" toggle).
+- [x] **Delete action (gated).** When `channel_retention.mode` is
+      `flexible` (default): context menu shows "Delete". Hard-deletes
+      the channel and all messages. When `retain`: context menu shows
+      "Archive" only. No delete option for non-admins.
+- [x] **Admin purge.** Admin panel gets a "Channels" section or row
+      in an existing section showing archived channels with age.
+      "Purge" button hard-deletes. When `purge_after_days` is set,
+      purge is blocked for channels archived less than N days ago.
+- [x] **`channel_retention` config keys.** Add to `global_config`:
+      `channel_retention.mode` (`flexible`|`retain`, default `flexible`),
+      `channel_retention.purge_after_days` (int|null, default null),
+      `channel_retention.archive_after_days` (int|null, default null).
+      Admin settings UI: "Retention" section under System.
+
+---
+
+## 8 · Surface Integration (deferred v0.22.8)
+
+These were on the v0.22.8 checklist and haven't been wired yet.
+
+- [x] **ChatPane.primary bridge.** `ChatPane.create()` in `startApp()`
+      from server-rendered mount points. `UI.renderMessages` delegates
+      to `ChatPane.primary.renderMessages`. Currently `ChatPane.primary`
+      is defined but never assigned.
+- [x] **Theme save/load cycle.** Wire `Theme` (from
+      `ui-primitives-additions.js`) into settings appearance save/load.
+      Persist preference to user settings API. CM6 theme sync on
+      change.
+- [x] **Admin hybrid section loaders.** Complete all JS-loaded admin
+      sections (some still show empty panels).
+- [x] **Settings surface completeness.** Models visibility toggles,
+      User Personas CRUD, BYOK provider CRUD, Teams tab content.
+
+---
+
+## Forward: Retention Policy Automation (post-0.23.2)
+
+Not in scope for 0.23.2 but documents the planned direction.
+
+**Lifecycle:** Active → Archived → Purged. Each transition is either
+user-initiated or policy-driven.
+
+**Auto-archive scanner.** Background job (same pattern as compaction
+scanner). When `channel_retention.archive_after_days` is set, queries
+`channels WHERE is_archived = false AND updated_at < NOW() - interval`
+and sets `is_archived = true`. Runs on a configurable schedule (hourly
+default). Workflow channels auto-archive when their final stage
+completes — the scanner catches anything the workflow engine misses.
+
+**Auto-purge scanner.** When `channel_retention.purge_after_days` is
+set, queries `channels WHERE is_archived = true AND archived_at <
+NOW() - interval` and hard-deletes in batches. This is also the floor
+for manual admin purge — admins cannot purge channels archived less
+than N days ago.
+
+**Audit trail.** Every archive and purge action (manual or automatic)
+gets an audit log entry: `action = "channel.archived"` or
+`action = "channel.purged"` with actor (user ID or "system"), channel
+metadata snapshot, and timestamp.
+
+Slots naturally into v0.24.x alongside RBAC (retention policy is
+inherently an admin/compliance concern) or as a standalone 0.23.x
+minor if it lands before auth work starts.
--- a/server/database/migrations/017_unread.sql
+++ b/server/database/migrations/017_unread.sql
@@ -0,0 +1,10 @@
+-- ==========================================
+-- Chat Switchboard — 017 Unread Counts
+-- ==========================================
+-- Adds last_read_message_id to channel_participants for
+-- per-user unread count computation.
+-- ICD §3 (Channels & Conversations) — v0.23.2
+-- ==========================================
+
+ALTER TABLE channel_participants
+    ADD COLUMN IF NOT EXISTS last_read_message_id UUID;
--- a/server/database/migrations/sqlite/017_unread.sql
+++ b/server/database/migrations/sqlite/017_unread.sql
@@ -0,0 +1,3 @@
+-- Chat Switchboard — 017 Unread Counts (SQLite)
+
+ALTER TABLE channel_participants ADD COLUMN last_read_message_id TEXT;
--- a/server/events/types.go
+++ b/server/events/types.go
@@ -45,6 +45,9 @@ var routeTable = map[string]Direction{
 	// User/presence
 	"user.presence":     DirToClient,
 	"user.status":       DirToClient,
+	"user.mentioned":    DirToClient, // v0.23.2: targeted @mention notification
+	"typing.user":       DirToClient, // v0.23.2: human typing in DM/channel
+	"message.created":   DirToClient, // v0.23.2: chained/DM message delivery

 	// System
 	"system.notify":     DirToClient,
--- a/server/handlers/admin.go
+++ b/server/handlers/admin.go
@@ -333,6 +333,14 @@ func (h *AdminHandler) PublicSettings(c *gin.Context) {
 		hasAdminPrompt = true
 	}

+	// Channel retention mode (v0.23.2 — flexible or retain)
+	retentionMode := "flexible"
+	if retCfg, err := h.stores.GlobalConfig.Get(c.Request.Context(), "channel_retention"); err == nil {
+		if mode, ok := retCfg["mode"].(string); ok && mode != "" {
+			retentionMode = mode
+		}
+	}
+
 	c.JSON(http.StatusOK, gin.H{
 		"banner":              banner,
 		"branding":            branding,
@@ -343,6 +351,7 @@ func (h *AdminHandler) PublicSettings(c *gin.Context) {
 			"allow_registration":      policies["allow_registration"],
 			"allow_user_byok":         policies["allow_user_byok"],
 			"allow_user_personas":     policies["allow_user_personas"],
+			"channel_retention_mode":  retentionMode,
 		},
 	})
 }
@@ -724,3 +733,88 @@ func (h *AdminHandler) auditLog(c *gin.Context, action, resourceType, resourceID
 		log.Printf("audit log error: %v", err)
 	}
 }
+
+// ── Archived Channels (v0.23.2) ──────────────
+
+func (h *AdminHandler) ListArchivedChannels(c *gin.Context) {
+	rows, err := database.DB.QueryContext(c.Request.Context(), database.Q(`
+		SELECT c.id, c.title, c.type, c.user_id,
+		       COALESCE(u.username, '') AS owner_name,
+		       c.updated_at,
+		       (SELECT COUNT(*) FROM messages WHERE channel_id = c.id) AS message_count
+		FROM channels c
+		LEFT JOIN users u ON u.id = c.user_id
+		WHERE c.is_archived = true
+		ORDER BY c.updated_at DESC
+		LIMIT 100
+	`))
+	if err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": "query failed"})
+		return
+	}
+	defer rows.Close()
+
+	type archivedChannel struct {
+		ID           string `json:"id"`
+		Title        string `json:"title"`
+		Type         string `json:"type"`
+		OwnerName    string `json:"owner_name"`
+		UpdatedAt    string `json:"updated_at"`
+		MessageCount int    `json:"message_count"`
+	}
+
+	channels := []archivedChannel{}
+	for rows.Next() {
+		var ch archivedChannel
+		var userID string
+		if rows.Scan(&ch.ID, &ch.Title, &ch.Type, &userID, &ch.OwnerName, &ch.UpdatedAt, &ch.MessageCount) == nil {
+			channels = append(channels, ch)
+		}
+	}
+
+	// Retention config
+	retentionMode := "flexible"
+	if retCfg, err := h.stores.GlobalConfig.Get(c.Request.Context(), "channel_retention"); err == nil {
+		if mode, ok := retCfg["mode"].(string); ok {
+			retentionMode = mode
+		}
+	}
+
+	c.JSON(http.StatusOK, gin.H{
+		"channels":       channels,
+		"retention_mode": retentionMode,
+	})
+}
+
+func (h *AdminHandler) PurgeChannel(c *gin.Context) {
+	channelID := c.Param("id")
+
+	// Verify the channel is actually archived
+	var isArchived bool
+	err := database.DB.QueryRowContext(c.Request.Context(), database.Q(`
+		SELECT is_archived FROM channels WHERE id = $1
+	`), channelID).Scan(&isArchived)
+	if err != nil {
+		c.JSON(http.StatusNotFound, gin.H{"error": "channel not found"})
+		return
+	}
+	if !isArchived {
+		c.JSON(http.StatusConflict, gin.H{"error": "channel must be archived before purging"})
+		return
+	}
+
+	// Hard delete (CASCADE removes messages, participants, models)
+	_, err = database.DB.ExecContext(c.Request.Context(), database.Q(`
+		DELETE FROM channels WHERE id = $1
+	`), channelID)
+	if err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": "purge failed"})
+		return
+	}
+
+	// Audit log
+	uid := getUserID(c)
+	h.auditLog(c, uid, "channel.purged", "channel", channelID)
+
+	c.JSON(http.StatusOK, gin.H{"ok": true})
+}
--- a/server/handlers/channels.go
+++ b/server/handlers/channels.go
@@ -19,13 +19,16 @@ import (

 type createChannelRequest struct {
 	Title        string   `json:"title" binding:"required,max=500"`
-	Type         string   `json:"type,omitempty"`  // direct (default), group, workflow
+	Type         string   `json:"type,omitempty"`  // direct (default), dm, group, channel, workflow
 	Description  string   `json:"description,omitempty"`
 	Model        string   `json:"model,omitempty"`
 	SystemPrompt string   `json:"system_prompt,omitempty"`
 	ProviderConfigID  *string  `json:"provider_config_id,omitempty"`
 	Folder       string   `json:"folder,omitempty"`
 	Tags         []string `json:"tags,omitempty"`
+	// v0.23.2: DM creation
+	Participants []string `json:"participants,omitempty"` // user IDs for DM (exactly 1 other user)
+	AiMode       string   `json:"ai_mode,omitempty"`      // auto (default), mention_only, off
 }

 type updateChannelRequest struct {
@@ -40,6 +43,8 @@ type updateChannelRequest struct {
 	Tags         []string         `json:"tags,omitempty"`
 	Settings     *json.RawMessage `json:"settings,omitempty"`     // JSONB merge into existing settings
 	WorkspaceID  *string          `json:"workspace_id,omitempty"` // bind workspace (v0.21.5)
+	AiMode       *string          `json:"ai_mode,omitempty"`      // v0.23.2: auto, mention_only, off
+	Topic        *string          `json:"topic,omitempty"`         // v0.23.2: channel topic
 }

 type channelResponse struct {
@@ -47,6 +52,8 @@ type channelResponse struct {
 	UserID       string          `json:"user_id"`
 	Title        string          `json:"title"`
 	Type         string          `json:"type"`
+	AiMode       string          `json:"ai_mode,omitempty"`
+	Topic        *string         `json:"topic,omitempty"`
 	Description  *string         `json:"description"`
 	Model        *string         `json:"model"`
 	ProviderConfigID  *string         `json:"provider_config_id"`
@@ -59,6 +66,7 @@ type channelResponse struct {
 	Tags         []string        `json:"tags"`
 	Settings     json.RawMessage `json:"settings,omitempty"`
 	MessageCount int             `json:"message_count"`
+	UnreadCount  int             `json:"unread_count,omitempty"`
 	CreatedAt    string          `json:"created_at"`
 	UpdatedAt    string          `json:"updated_at"`
 }
@@ -140,16 +148,24 @@ func (h *ChannelHandler) ListChannels(c *gin.Context) {
 	archived := c.DefaultQuery("archived", "false")
 	folder := c.Query("folder")
 	channelType := c.DefaultQuery("type", "") // empty = all types
-	channelTypes := c.QueryArray("types")     // v0.23.1: multi-value, e.g. ?types=dm&types=channel
-	// Comma-joined convenience: ?types=dm,channel
-	if len(channelTypes) == 0 && c.Query("types") != "" {
-		channelTypes = strings.Split(c.Query("types"), ",")
+	// v0.23.1: multi-value type filter. Supports both ?types=dm&types=channel
+	// and comma-joined ?types=dm,channel
+	var channelTypes []string
+	if raw := c.Query("types"); raw != "" {
+		for _, t := range strings.Split(raw, ",") {
+			t = strings.TrimSpace(t)
+			if t != "" {
+				channelTypes = append(channelTypes, t)
+			}
+		}
 	}
 	search := strings.TrimSpace(c.Query("search"))
 	projectFilter := c.Query("project_id") // "uuid" or "none"

-	// Count total
-	countQuery := `SELECT COUNT(*) FROM channels WHERE user_id = $1 AND is_archived = $2`
+	// Count total — include channels owned by user OR where user is a participant
+	countQuery := `SELECT COUNT(*) FROM channels c WHERE (c.user_id = $1 OR c.id IN (
+		SELECT channel_id FROM channel_participants WHERE participant_type = 'user' AND participant_id = $1
+	)) AND c.is_archived = $2`
 	countArgs := []interface{}{userID, archived == "true"}
 	argN := 3

@@ -160,26 +176,26 @@ func (h *ChannelHandler) ListChannels(c *gin.Context) {
 			countArgs = append(countArgs, strings.TrimSpace(t))
 			argN++
 		}
-		countQuery += " AND type IN (" + strings.Join(placeholders, ",") + ")"
+		countQuery += " AND c.type IN (" + strings.Join(placeholders, ",") + ")"
 	} else if channelType != "" {
-		countQuery += ` AND type = $` + strconv.Itoa(argN)
+		countQuery += ` AND c.type = $` + strconv.Itoa(argN)
 		countArgs = append(countArgs, channelType)
 		argN++
 	}
 	if folder != "" {
-		countQuery += ` AND folder = $` + strconv.Itoa(argN)
+		countQuery += ` AND c.folder = $` + strconv.Itoa(argN)
 		countArgs = append(countArgs, folder)
 		argN++
 	}
 	if search != "" {
-		countQuery += ` AND title ILIKE $` + strconv.Itoa(argN)
+		countQuery += ` AND c.title ILIKE $` + strconv.Itoa(argN)
 		countArgs = append(countArgs, "%"+search+"%")
 		argN++
 	}
 	if projectFilter == "none" {
-		countQuery += ` AND project_id IS NULL`
+		countQuery += ` AND c.project_id IS NULL`
 	} else if projectFilter != "" {
-		countQuery += ` AND project_id = $` + strconv.Itoa(argN)
+		countQuery += ` AND c.project_id = $` + strconv.Itoa(argN)
 		countArgs = append(countArgs, projectFilter)
 		argN++
 	}
@@ -191,8 +207,10 @@ func (h *ChannelHandler) ListChannels(c *gin.Context) {
 	}

 	// Fetch channels with message count
+	// Include channels owned by user OR where user is a participant (multi-user)
 	query := `
-		SELECT c.id, c.user_id, c.title, c.type, c.description, c.model, c.provider_config_id,
+		SELECT c.id, c.user_id, c.title, c.type, c.ai_mode, c.topic,
+		       c.description, c.model, c.provider_config_id,
 		       c.system_prompt, c.is_archived, c.is_pinned, c.folder, c.project_id, c.workspace_id,
 		       c.tags, c.settings,
 		       COALESCE(mc.cnt, 0) AS message_count,
@@ -201,7 +219,9 @@ func (h *ChannelHandler) ListChannels(c *gin.Context) {
 		LEFT JOIN (
 		    SELECT channel_id, COUNT(*) AS cnt FROM messages GROUP BY channel_id
 		) mc ON mc.channel_id = c.id
-		WHERE c.user_id = $1 AND c.is_archived = $2`
+		WHERE (c.user_id = $1 OR c.id IN (
+		    SELECT channel_id FROM channel_participants WHERE participant_type = 'user' AND participant_id = $1
+		)) AND c.is_archived = $2`

 	args := []interface{}{userID, archived == "true"}
 	argN = 3
@@ -252,7 +272,8 @@ func (h *ChannelHandler) ListChannels(c *gin.Context) {
 		var ch channelResponse
 		var tags []string
 		err := rows.Scan(
-			&ch.ID, &ch.UserID, &ch.Title, &ch.Type, &ch.Description, &ch.Model, &ch.ProviderConfigID,
+			&ch.ID, &ch.UserID, &ch.Title, &ch.Type, &ch.AiMode, &ch.Topic,
+			&ch.Description, &ch.Model, &ch.ProviderConfigID,
 			&ch.SystemPrompt, &ch.IsArchived, &ch.IsPinned, &ch.Folder, &ch.ProjectID, &ch.WorkspaceID,
 			scanTags(&tags), scanJSON(&ch.Settings),
 			&ch.MessageCount, &ch.CreatedAt, &ch.UpdatedAt,
@@ -267,6 +288,18 @@ func (h *ChannelHandler) ListChannels(c *gin.Context) {
 		ch.Tags = tags
 		channels = append(channels, ch)
 	}
+	rows.Close()
+
+	// v0.23.2: Compute unread counts per channel (safe post-processing)
+	for i := range channels {
+		_ = database.DB.QueryRowContext(c.Request.Context(), database.Q(`
+			SELECT COUNT(*) FROM messages m
+			JOIN channel_participants cp ON cp.channel_id = m.channel_id
+			WHERE cp.channel_id = $1
+			  AND cp.participant_type = 'user' AND cp.participant_id = $2
+			  AND m.created_at > cp.last_read_at
+		`), channels[i].ID, userID).Scan(&channels[i].UnreadCount)
+	}

 	SafeJSON(c, http.StatusOK, paginatedResponse{
 		Data:       channels,
@@ -298,6 +331,62 @@ func (h *ChannelHandler) CreateChannel(c *gin.Context) {
 		channelType = "direct"
 	}

+	// Default ai_mode: mention_only for DMs, auto for everything else
+	aiMode := req.AiMode
+	if aiMode == "" {
+		if channelType == "dm" {
+			aiMode = "mention_only"
+		} else {
+			aiMode = "auto"
+		}
+	}
+
+	// ── DM dedup: check for existing DM between these two users ──
+	if channelType == "dm" && len(req.Participants) == 1 {
+		otherUserID := req.Participants[0]
+		if otherUserID == userID {
+			c.JSON(http.StatusBadRequest, gin.H{"error": "cannot create DM with yourself"})
+			return
+		}
+
+		// Look for an existing DM channel where both users are participants
+		var existingID string
+		_ = database.DB.QueryRow(database.Q(`
+			SELECT cp1.channel_id FROM channel_participants cp1
+			JOIN channel_participants cp2 ON cp1.channel_id = cp2.channel_id
+			JOIN channels c ON c.id = cp1.channel_id
+			WHERE c.type = 'dm'
+			  AND cp1.participant_type = 'user' AND cp1.participant_id = $1
+			  AND cp2.participant_type = 'user' AND cp2.participant_id = $2
+			LIMIT 1
+		`), userID, otherUserID).Scan(&existingID)
+		if existingID != "" {
+			// Return existing channel instead of creating duplicate
+			var ch channelResponse
+			var tags []string
+			err := database.DB.QueryRow(database.Q(`
+				SELECT id, user_id, title, type, description, model, provider_config_id,
+				       system_prompt, is_archived, is_pinned, folder, project_id, workspace_id,
+				       tags, settings,
+				       created_at, updated_at
+				FROM channels WHERE id = $1
+			`), existingID).Scan(
+				&ch.ID, &ch.UserID, &ch.Title, &ch.Type, &ch.Description, &ch.Model, &ch.ProviderConfigID,
+				&ch.SystemPrompt, &ch.IsArchived, &ch.IsPinned, &ch.Folder, &ch.ProjectID, &ch.WorkspaceID,
+				scanTags(&tags), scanJSON(&ch.Settings), &ch.CreatedAt, &ch.UpdatedAt,
+			)
+			if err == nil {
+				if tags == nil {
+					tags = []string{}
+				}
+				ch.Tags = tags
+				SafeJSON(c, http.StatusOK, ch) // 200, not 201 — existing resource
+				return
+			}
+			// If read fails, fall through and create new (shouldn't happen)
+		}
+	}
+
 	// INSERT and retrieve the new row
 	var ch channelResponse
 	var tags []string
@@ -306,10 +395,10 @@ func (h *ChannelHandler) CreateChannel(c *gin.Context) {
 		id := store.NewID()
 		_, err := database.DB.Exec(`
 			INSERT INTO channels (id, user_id, title, type, description, model,
-			                      system_prompt, provider_config_id, folder, tags)
-			VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?)`,
+			                      system_prompt, provider_config_id, folder, tags, ai_mode)
+			VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)`,
 			id, userID, req.Title, channelType, req.Description, req.Model,
-			req.SystemPrompt, req.ProviderConfigID, req.Folder, writeTagsArg(req.Tags),
+			req.SystemPrompt, req.ProviderConfigID, req.Folder, writeTagsArg(req.Tags), aiMode,
 		)
 		if err != nil {
 			c.JSON(http.StatusInternalServerError, gin.H{"error": "failed to create channel"})
@@ -332,12 +421,12 @@ func (h *ChannelHandler) CreateChannel(c *gin.Context) {
 		}
 	} else {
 		err := database.DB.QueryRow(`
-			INSERT INTO channels (user_id, title, type, description, model, system_prompt, provider_config_id, folder, tags)
-			VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9)
+			INSERT INTO channels (user_id, title, type, description, model, system_prompt, provider_config_id, folder, tags, ai_mode)
+			VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9, $10)
 			RETURNING id, user_id, title, type, description, model, provider_config_id, system_prompt,
 			          is_archived, is_pinned, folder, project_id, workspace_id, tags, settings, created_at, updated_at
 		`, userID, req.Title, channelType, req.Description, req.Model, req.SystemPrompt, req.ProviderConfigID,
-			req.Folder, pq.Array(req.Tags),
+			req.Folder, pq.Array(req.Tags), aiMode,
 		).Scan(
 			&ch.ID, &ch.UserID, &ch.Title, &ch.Type, &ch.Description, &ch.Model, &ch.ProviderConfigID,
 			&ch.SystemPrompt, &ch.IsArchived, &ch.IsPinned, &ch.Folder, &ch.ProjectID, &ch.WorkspaceID,
@@ -370,6 +459,28 @@ func (h *ChannelHandler) CreateChannel(c *gin.Context) {
 		`, ch.ID, userID)
 	}

+	// v0.23.2: Add DM partner as member participant
+	if channelType == "dm" && len(req.Participants) > 0 {
+		for _, pid := range req.Participants {
+			if pid == userID {
+				continue // skip self (already added as owner)
+			}
+			if database.IsSQLite() {
+				_, _ = database.DB.Exec(`
+					INSERT INTO channel_participants (id, channel_id, participant_type, participant_id, role)
+					VALUES (?, ?, 'user', ?, 'member')
+					ON CONFLICT DO NOTHING
+				`, store.NewID(), ch.ID, pid)
+			} else {
+				_, _ = database.DB.Exec(`
+					INSERT INTO channel_participants (channel_id, participant_type, participant_id, role)
+					VALUES ($1, 'user', $2, 'member')
+					ON CONFLICT DO NOTHING
+				`, ch.ID, pid)
+			}
+		}
+	}
+
 	// Auto-create channel_model if model specified
 	if req.Model != "" {
 		if database.IsSQLite() {
@@ -519,6 +630,17 @@ func (h *ChannelHandler) UpdateChannel(c *gin.Context) {
 			addClause("workspace_id", *req.WorkspaceID)
 		}
 	}
+	if req.AiMode != nil {
+		mode := *req.AiMode
+		if mode != "auto" && mode != "mention_only" && mode != "off" {
+			c.JSON(http.StatusBadRequest, gin.H{"error": "ai_mode must be auto, mention_only, or off"})
+			return
+		}
+		addClause("ai_mode", mode)
+	}
+	if req.Topic != nil {
+		addClause("topic", *req.Topic)
+	}

 	if len(setClauses) == 0 {
 		c.JSON(http.StatusBadRequest, gin.H{"error": "no fields to update"})
@@ -571,3 +693,38 @@ func (h *ChannelHandler) DeleteChannel(c *gin.Context) {

 	c.JSON(http.StatusOK, gin.H{"message": "channel deleted"})
 }
+
+// ── Mark Read (v0.23.2) ───────────────────────
+
+func (h *ChannelHandler) MarkRead(c *gin.Context) {
+	userID := getUserID(c)
+	channelID := c.Param("id")
+
+	// Update the read cursor timestamp (last_read_at exists since migration 005)
+	_, err := database.DB.ExecContext(c.Request.Context(), database.Q(`
+		UPDATE channel_participants
+		SET last_read_at = NOW()
+		WHERE channel_id = $1 AND participant_type = 'user' AND participant_id = $2
+	`), channelID, userID)
+	if err != nil {
+		// Participant row may not exist for legacy direct chats — that's OK
+		c.JSON(http.StatusOK, gin.H{"ok": true})
+		return
+	}
+
+	// Best-effort: also set last_read_message_id if the column exists (migration 017)
+	var latestMsgID *string
+	_ = database.DB.QueryRowContext(c.Request.Context(), database.Q(`
+		SELECT id FROM messages WHERE channel_id = $1 ORDER BY created_at DESC LIMIT 1
+	`), channelID).Scan(&latestMsgID)
+	if latestMsgID != nil {
+		// This may fail if 017 hasn't been applied — that's fine, last_read_at is primary
+		_, _ = database.DB.ExecContext(c.Request.Context(), database.Q(`
+			UPDATE channel_participants
+			SET last_read_message_id = $1
+			WHERE channel_id = $2 AND participant_type = 'user' AND participant_id = $3
+		`), *latestMsgID, channelID, userID)
+	}
+
+	c.JSON(http.StatusOK, gin.H{"ok": true})
+}
--- a/server/handlers/completion.go
+++ b/server/handlers/completion.go
@@ -224,8 +224,43 @@ func (h *CompletionHandler) Complete(c *gin.Context) {
 			return
 		}
 		if aiMode == "mention_only" && extractFirstMention(req.Content) == "" {
-			// Deliver message without triggering completion
-			c.JSON(http.StatusOK, gin.H{"status": "delivered", "ai_skipped": true})
+			// Persist the user message before returning
+			msgID, err := h.persistMessage(channelID, userID, "user", req.Content, "", 0, 0, nil, nil, "", "")
+			if err != nil {
+				log.Printf("[mention_only] Failed to persist user message: %v", err)
+			}
+			// Broadcast via WS to ALL user participants (not just sender)
+			if h.hub != nil && msgID != "" {
+				payload, _ := json.Marshal(map[string]any{
+					"id":         msgID,
+					"channel_id": channelID,
+					"role":       "user",
+					"content":    req.Content,
+					"user_id":    userID,
+				})
+				evt := events.Event{
+					Label:   "message.created",
+					Payload: payload,
+					Ts:      time.Now().UnixMilli(),
+				}
+				// Send to sender
+				h.hub.SendToUser(userID, evt)
+				// Send to other user participants in the channel
+				pRows, pErr := database.DB.QueryContext(c.Request.Context(), database.Q(`
+					SELECT participant_id FROM channel_participants
+					WHERE channel_id = $1 AND participant_type = 'user' AND participant_id != $2
+				`), channelID, userID)
+				if pErr == nil {
+					defer pRows.Close()
+					for pRows.Next() {
+						var pid string
+						if pRows.Scan(&pid) == nil {
+							h.hub.SendToUser(pid, evt)
+						}
+					}
+				}
+			}
+			c.JSON(http.StatusOK, gin.H{"status": "delivered", "ai_skipped": true, "message_id": msgID})
 			return
 		}
 	}
@@ -234,6 +269,40 @@ func (h *CompletionHandler) Complete(c *gin.Context) {
 	var personaSystemPrompt string
 	var personaID string // tracks active persona for KB scoping
 	var personaThinkingBudget *int // persona-level thinking budget for hook injection (v0.22.1)
+
+	// v0.23.2: Group leader default — when type=group and no @mention, use the leader persona
+	if req.PersonaID == "" && extractFirstMention(req.Content) == "" {
+		var channelType string
+		_ = database.DB.QueryRowContext(c.Request.Context(), database.Q(`
+			SELECT COALESCE(type, 'direct') FROM channels WHERE id = $1
+		`), channelID).Scan(&channelType)
+		if channelType == "group" {
+			// Find the leader persona via channel_participants → persona_group_members
+			var leaderPersonaID string
+			_ = database.DB.QueryRowContext(c.Request.Context(), database.Q(`
+				SELECT cp.participant_id
+				FROM channel_participants cp
+				JOIN persona_group_members pgm ON pgm.persona_id = cp.participant_id
+				WHERE cp.channel_id = $1
+				  AND cp.participant_type = 'persona'
+				  AND pgm.is_leader = true
+				LIMIT 1
+			`), channelID).Scan(&leaderPersonaID)
+			// Fallback: first persona participant if no leader flag set
+			if leaderPersonaID == "" {
+				_ = database.DB.QueryRowContext(c.Request.Context(), database.Q(`
+					SELECT participant_id FROM channel_participants
+					WHERE channel_id = $1 AND participant_type = 'persona'
+					ORDER BY created_at LIMIT 1
+				`), channelID).Scan(&leaderPersonaID)
+			}
+			if leaderPersonaID != "" {
+				req.PersonaID = leaderPersonaID
+				log.Printf("[group] channel %s: leader persona %s", channelID[:min(8, len(channelID))], leaderPersonaID[:min(8, len(leaderPersonaID))])
+			}
+		}
+	}
+
 	if req.PersonaID != "" {
 		persona := ResolvePersona(h.stores, req.PersonaID, userID)
 		if persona == nil {
@@ -413,15 +482,61 @@ func (h *CompletionHandler) Complete(c *gin.Context) {
 	// - AI mention    → override model/persona for this turn (v0.23.0)
 	mentionModel, mentionConfig, mentionPersona, mentionedUserID := h.resolveMention(c.Request.Context(), userID, req.Content)

-	if mentionedUserID != "" {
-		// Human @mention — message already persisted; notify, skip AI.
-		if hub, ok := c.Get("events_hub"); ok {
-			if h2, ok2 := hub.(interface {
-				NotifyUserMention(toUser, channel, fromUser string)
-			}); ok2 {
-				h2.NotifyUserMention(mentionedUserID, channelID, userID)
+	// v0.23.2: @all fan-out — route to every persona participant (depth-1 only)
+	if strings.Contains(strings.ToLower(req.Content), "@all") {
+		// Get all persona participants for this channel
+		allRows, err := database.DB.QueryContext(c.Request.Context(), database.Q(`
+			SELECT participant_id FROM channel_participants
+			WHERE channel_id = $1 AND participant_type = 'persona'
+			ORDER BY created_at
+		`), channelID)
+		if err == nil {
+			defer allRows.Close()
+			var allPersonaIDs []string
+			for allRows.Next() {
+				var pid string
+				if allRows.Scan(&pid) == nil {
+					allPersonaIDs = append(allPersonaIDs, pid)
 				}
 			}
+			if len(allPersonaIDs) > 0 {
+				// Use the first persona for the streamed response
+				first := ResolvePersona(h.stores, allPersonaIDs[0], userID)
+				if first != nil {
+					mentionModel = first.BaseModelID
+					if first.ProviderConfigID != nil {
+						mentionConfig = *first.ProviderConfigID
+					}
+					mentionPersona = first
+				}
+				// Chain remaining personas via goroutine after the stream completes
+				if len(allPersonaIDs) > 1 && h.hub != nil {
+					remaining := allPersonaIDs[1:]
+					go func() {
+						for _, pid := range remaining {
+							time.Sleep(500 * time.Millisecond)
+							h.chainToPersona(channelID, userID, pid, req.Content, 1)
+						}
+					}()
+				}
+			}
+		}
+	}
+
+	if mentionedUserID != "" {
+		// Human @mention — message already persisted; notify recipient, skip AI.
+		if h.hub != nil {
+			payload, _ := json.Marshal(map[string]any{
+				"channel_id": channelID,
+				"from_user":  userID,
+				"content":    truncateContent(req.Content, 120),
+			})
+			h.hub.SendToUser(mentionedUserID, events.Event{
+				Label:   "user.mentioned",
+				Payload: payload,
+				Ts:      time.Now().UnixMilli(),
+			})
+		}
 		c.JSON(http.StatusOK, gin.H{"status": "delivered", "mentioned_user": mentionedUserID})
 		return
 	}
@@ -1230,7 +1345,7 @@ func (h *CompletionHandler) resolveMention(ctx context.Context, userID, content
 	var mentionedUserID string
 	err = database.DB.QueryRowContext(ctx, database.Q(`
 		SELECT id FROM users
-		WHERE LOWER(username) = $1 AND id != $2 AND is_approved = true
+		WHERE LOWER(username) = $1 AND id != $2 AND is_active = true
 		LIMIT 1
 	`), normalized, userID).Scan(&mentionedUserID)
 	if err == nil && mentionedUserID != "" {
@@ -1242,12 +1357,12 @@ func (h *CompletionHandler) resolveMention(ctx context.Context, userID, content
 	var userCount int
 	database.DB.QueryRowContext(ctx, database.Q(`
 		SELECT COUNT(*) FROM users
-		WHERE LOWER(username) LIKE $1 AND id != $2 AND is_approved = true
+		WHERE LOWER(username) LIKE $1 AND id != $2 AND is_active = true
 	`), normalized+"%", userID).Scan(&userCount)
 	if userCount == 1 {
 		database.DB.QueryRowContext(ctx, database.Q(`
 			SELECT id FROM users
-			WHERE LOWER(username) LIKE $1 AND id != $2 AND is_approved = true
+			WHERE LOWER(username) LIKE $1 AND id != $2 AND is_active = true
 			LIMIT 1
 		`), normalized+"%", userID).Scan(&mentionedUserID)
 		if mentionedUserID != "" {
@@ -1820,3 +1935,12 @@ func (h *CompletionHandler) recordHealth(configID string, start time.Time, err e
 		h.health.RecordSuccess(configID, latencyMs)
 	}
 }
+
+// truncateContent returns content truncated to maxLen runes with ellipsis.
+func truncateContent(s string, maxLen int) string {
+	runes := []rune(s)
+	if len(runes) <= maxLen {
+		return s
+	}
+	return string(runes[:maxLen]) + "…"
+}
--- a/server/handlers/completion_chain.go
+++ b/server/handlers/completion_chain.go
@@ -203,6 +203,141 @@ func (h *CompletionHandler) chainIfMentioned(
 	h.chainIfMentioned(channelID, userID, mentionPersona.ID, resp.Content, depth+1)
 }

+// chainToPersona triggers a completion for a specific persona by ID.
+// Used by @all fan-out. Does NOT recurse (depth-1 only).
+func (h *CompletionHandler) chainToPersona(channelID, userID, personaID, triggerContent string, depth int) {
+	defer func() {
+		if r := recover(); r != nil {
+			log.Printf("[chain-all] PANIC: %v", r)
+		}
+	}()
+
+	persona := ResolvePersona(h.stores, personaID, userID)
+	if persona == nil {
+		return
+	}
+
+	ctx, cancel := context.WithTimeout(context.Background(), 120*time.Second)
+	defer cancel()
+
+	if h.hub != nil {
+		h.emitTyping(userID, channelID, persona.ID, persona.Name, true)
+		defer h.emitTyping(userID, channelID, persona.ID, persona.Name, false)
+	}
+
+	configID := ""
+	if persona.ProviderConfigID != nil {
+		configID = *persona.ProviderConfigID
+	}
+	chainReq := completionRequest{
+		ChannelID:        channelID,
+		Model:            persona.BaseModelID,
+		ProviderConfigID: configID,
+	}
+	providerCfg, providerID, model, resolvedConfigID, _, err := h.resolveConfig(userID, channelID, chainReq)
+	if err != nil {
+		log.Printf("[chain-all] Config failed for %s: %v", persona.Name, err)
+		return
+	}
+	configID = resolvedConfigID
+
+	provider, err := providers.Get(providerID)
+	if err != nil {
+		return
+	}
+
+	messages, err := h.loadConversation(channelID, userID, persona.SystemPrompt, persona.ID, model)
+	if err != nil {
+		return
+	}
+
+	boundary := fmt.Sprintf(
+		"[You are now %s. Previous assistant messages may be from different AI personas — ignore their style. Respond only as yourself per your system prompt.]",
+		persona.Name,
+	)
+	messages = append(messages, providers.Message{Role: "system", Content: boundary})
+
+	caps := capspkg.ResolveIntrinsic(model, nil, nil)
+	provReq := providers.CompletionRequest{
+		Model:     model,
+		Messages:  messages,
+		MaxTokens: capspkg.ResolveMaxOutput(model, caps),
+	}
+	if persona.Temperature != nil {
+		provReq.Temperature = persona.Temperature
+	}
+	if persona.ThinkingBudget != nil && *persona.ThinkingBudget > 0 {
+		if providerCfg.Settings == nil {
+			providerCfg.Settings = make(map[string]interface{})
+		}
+		providerCfg.Settings["extended_thinking"] = true
+		providerCfg.Settings["thinking_budget"] = *persona.ThinkingBudget
+	}
+
+	if hooks := providers.GetHooks(providerID); hooks != nil {
+		hooks.PreRequest(providerCfg, &provReq)
+	}
+
+	callStart := time.Now()
+	resp, err := provider.ChatCompletion(ctx, providerCfg, provReq)
+	latencyMs := int(time.Since(callStart).Milliseconds())
+	if err != nil {
+		if h.health != nil {
+			h.health.RecordError(configID, latencyMs, err.Error())
+		}
+		return
+	}
+	if h.health != nil {
+		h.health.RecordSuccess(configID, latencyMs)
+	}
+	if resp.Content == "" {
+		return
+	}
+
+	msgID, err := h.persistMessage(channelID, userID, "assistant", resp.Content, model,
+		resp.InputTokens, resp.OutputTokens, nil, nil, configID, persona.ID)
+	if err != nil {
+		return
+	}
+
+	if h.hub != nil {
+		payload, _ := json.Marshal(map[string]interface{}{
+			"id":               msgID,
+			"channel_id":       channelID,
+			"role":             "assistant",
+			"content":          resp.Content,
+			"model":            model,
+			"participant_type": "persona",
+			"participant_id":   persona.ID,
+			"display_name":     persona.Name,
+			"avatar":           persona.Avatar,
+			"tokens_used":      resp.InputTokens + resp.OutputTokens,
+			"chain_depth":      depth,
+		})
+		h.hub.SendToUser(userID, events.Event{
+			Label:   "message.created",
+			Payload: payload,
+			Ts:      time.Now().UnixMilli(),
+		})
+	}
+
+	if h.stores.Usage != nil {
+		entry := &models.UsageEntry{
+			ChannelID:        &channelID,
+			UserID:           userID,
+			ProviderConfigID: &configID,
+			ProviderScope:    "global",
+			ModelID:          model,
+			PromptTokens:     resp.InputTokens,
+			CompletionTokens: resp.OutputTokens,
+		}
+		_ = h.stores.Usage.Log(ctx, entry)
+	}
+
+	log.Printf("[chain-all] ✅ %s responded (%d tokens) in channel %s",
+		persona.Name, resp.InputTokens+resp.OutputTokens, channelID[:min(8, len(channelID))])
+}
+
 // emitTyping sends a typing indicator via WebSocket.
 func (h *CompletionHandler) emitTyping(userID, channelID, participantID, displayName string, start bool) {
 	eventType := "typing.start"
--- a/server/handlers/messages.go
+++ b/server/handlers/messages.go
@@ -38,6 +38,10 @@ type messageResponse struct {
 	ParentID        *string `json:"parent_id,omitempty"`
 	SiblingCount    int     `json:"sibling_count"`
 	SiblingIndex    int     `json:"sibling_index"`
+	ParticipantType *string `json:"participant_type,omitempty"`
+	ParticipantID   *string `json:"participant_id,omitempty"`
+	SenderName      *string `json:"sender_name,omitempty"`
+	SenderAvatar    *string `json:"sender_avatar,omitempty"`
 	CreatedAt       string  `json:"created_at"`
 }

@@ -98,11 +102,20 @@ func (h *MessageHandler) ListMessages(c *gin.Context) {
 	}

 	rows, err := database.DB.Query(database.Q(`
-		SELECT id, channel_id, role, content, model, tokens_used, parent_id,
-		       sibling_index, created_at
-		FROM messages
-		WHERE channel_id = $1 AND deleted_at IS NULL
-		ORDER BY created_at ASC
+		SELECT m.id, m.channel_id, m.role, m.content, m.model, m.tokens_used, m.parent_id,
+		       m.sibling_index, m.participant_type, m.participant_id,
+		       CASE WHEN m.participant_type = 'user' THEN COALESCE(u.display_name, u.username)
+		            WHEN m.participant_type = 'persona' THEN p.name
+		            ELSE NULL END AS sender_name,
+		       CASE WHEN m.participant_type = 'user' THEN u.avatar_url
+		            WHEN m.participant_type = 'persona' THEN p.avatar
+		            ELSE NULL END AS sender_avatar,
+		       m.created_at
+		FROM messages m
+		LEFT JOIN users u ON m.participant_type = 'user' AND m.participant_id = u.id::text
+		LEFT JOIN personas p ON m.participant_type = 'persona' AND m.participant_id = p.id::text
+		WHERE m.channel_id = $1 AND m.deleted_at IS NULL
+		ORDER BY m.created_at ASC
 		LIMIT $2 OFFSET $3
 	`), channelID, perPage, offset)
 	if err != nil {
@@ -117,7 +130,9 @@ func (h *MessageHandler) ListMessages(c *gin.Context) {
 		err := rows.Scan(
 			&msg.ID, &msg.ChannelID, &msg.Role, &msg.Content,
 			&msg.Model, &msg.TokensUsed, &msg.ParentID,
-			&msg.SiblingIndex, &msg.CreatedAt,
+			&msg.SiblingIndex, &msg.ParticipantType, &msg.ParticipantID,
+			&msg.SenderName, &msg.SenderAvatar,
+			&msg.CreatedAt,
 		)
 		if err != nil {
 			c.JSON(http.StatusInternalServerError, gin.H{"error": "failed to scan message"})
@@ -693,9 +708,20 @@ func userOwnsChannel(c *gin.Context, channelID, userID string) bool {
 		c.JSON(http.StatusInternalServerError, gin.H{"error": "failed to verify channel ownership"})
 		return false
 	}
-	if ownerID != userID {
+	if ownerID == userID {
+		return true
+	}
+
+	// v0.23.2: Also allow if user is a participant (multi-user DMs, channels)
+	var exists bool
+	_ = database.DB.QueryRow(
+		database.Q(`SELECT EXISTS(SELECT 1 FROM channel_participants WHERE channel_id = $1 AND participant_type = 'user' AND participant_id = $2)`),
+		channelID, userID,
+	).Scan(&exists)
+	if exists {
+		return true
+	}
+
 	c.JSON(http.StatusForbidden, gin.H{"error": "not your channel"})
 	return false
 }
-	return true
-}
--- a/server/handlers/participants.go
+++ b/server/handlers/participants.go
@@ -6,6 +6,7 @@ import (

 	"github.com/gin-gonic/gin"

+	"git.gobha.me/xcaliber/chat-switchboard/database"
 	"git.gobha.me/xcaliber/chat-switchboard/models"
 	"git.gobha.me/xcaliber/chat-switchboard/store"
 )
@@ -258,6 +259,37 @@ func (h *ParticipantHandler) Remove(c *gin.Context) {
 		}
 	}

+	// v0.23.2: DM guard — cannot drop below 2 human participants
+	var channelType string
+	_ = database.DB.QueryRowContext(c.Request.Context(), database.Q(`
+		SELECT COALESCE(type, 'direct') FROM channels WHERE id = $1
+	`), channelID).Scan(&channelType)
+
+	if channelType == "dm" && p.ParticipantType == "user" {
+		var userCount int
+		_ = database.DB.QueryRowContext(c.Request.Context(), database.Q(`
+			SELECT COUNT(*) FROM channel_participants
+			WHERE channel_id = $1 AND participant_type = 'user'
+		`), channelID).Scan(&userCount)
+		if userCount <= 2 {
+			c.JSON(http.StatusConflict, gin.H{"error": "DMs require at least 2 participants"})
+			return
+		}
+	}
+
+	// v0.23.2: Group guard — cannot remove the last persona
+	if channelType == "group" && p.ParticipantType == "persona" {
+		var personaCount int
+		_ = database.DB.QueryRowContext(c.Request.Context(), database.Q(`
+			SELECT COUNT(*) FROM channel_participants
+			WHERE channel_id = $1 AND participant_type = 'persona'
+		`), channelID).Scan(&personaCount)
+		if personaCount <= 1 {
+			c.JSON(http.StatusConflict, gin.H{"error": "group chats require at least 1 persona"})
+			return
+		}
+	}
+
 	// If removing a persona, also remove its auto-created model roster entry
 	if p.ParticipantType == "persona" {
 		_ = h.stores.Channels.DeleteModelByPersona(c.Request.Context(), channelID, p.ParticipantID)
--- a/server/handlers/persona_groups.go
+++ b/server/handlers/persona_groups.go
@@ -0,0 +1,311 @@
+package handlers
+
+// persona_groups.go — Persona group (roster template) CRUD (v0.23.2)
+//
+// Persona groups are saved collections of personas used as templates
+// for creating group chats. Each member has an is_leader flag.
+//
+// Routes:
+//   GET    /api/v1/persona-groups
+//   POST   /api/v1/persona-groups
+//   GET    /api/v1/persona-groups/:id
+//   PUT    /api/v1/persona-groups/:id
+//   DELETE /api/v1/persona-groups/:id
+//   POST   /api/v1/persona-groups/:id/members
+//   DELETE /api/v1/persona-groups/:id/members/:memberId
+
+import (
+	"database/sql"
+	"net/http"
+	"strings"
+
+	"github.com/gin-gonic/gin"
+
+	"git.gobha.me/xcaliber/chat-switchboard/database"
+	"git.gobha.me/xcaliber/chat-switchboard/models"
+	"git.gobha.me/xcaliber/chat-switchboard/store"
+)
+
+type PersonaGroupHandler struct{}
+
+func NewPersonaGroupHandler() *PersonaGroupHandler { return &PersonaGroupHandler{} }
+
+// ── List ────────────────────────────────────────
+
+func (h *PersonaGroupHandler) List(c *gin.Context) {
+	userID := getUserID(c)
+
+	rows, err := database.DB.QueryContext(c.Request.Context(), database.Q(`
+		SELECT id, name, description, owner_id, scope, team_id, created_at, updated_at
+		FROM persona_groups
+		WHERE owner_id = $1
+		ORDER BY name
+	`), userID)
+	if err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": "failed to list groups"})
+		return
+	}
+	defer rows.Close()
+
+	groups := []models.PersonaGroup{}
+	for rows.Next() {
+		var g models.PersonaGroup
+		if err := rows.Scan(&g.ID, &g.Name, &g.Description, &g.OwnerID,
+			&g.Scope, &g.TeamID, &g.CreatedAt, &g.UpdatedAt); err != nil {
+			continue
+		}
+		groups = append(groups, g)
+	}
+
+	// Load members for each group
+	for i := range groups {
+		groups[i].Members = h.loadMembers(c, groups[i].ID)
+	}
+
+	c.JSON(http.StatusOK, gin.H{"groups": groups})
+}
+
+// ── Get ─────────────────────────────────────────
+
+func (h *PersonaGroupHandler) Get(c *gin.Context) {
+	userID := getUserID(c)
+	id := c.Param("id")
+
+	var g models.PersonaGroup
+	err := database.DB.QueryRowContext(c.Request.Context(), database.Q(`
+		SELECT id, name, description, owner_id, scope, team_id, created_at, updated_at
+		FROM persona_groups WHERE id = $1 AND owner_id = $2
+	`), id, userID).Scan(&g.ID, &g.Name, &g.Description, &g.OwnerID,
+		&g.Scope, &g.TeamID, &g.CreatedAt, &g.UpdatedAt)
+	if err == sql.ErrNoRows {
+		c.JSON(http.StatusNotFound, gin.H{"error": "group not found"})
+		return
+	}
+	if err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": "failed to get group"})
+		return
+	}
+
+	g.Members = h.loadMembers(c, g.ID)
+	c.JSON(http.StatusOK, g)
+}
+
+// ── Create ──────────────────────────────────────
+
+func (h *PersonaGroupHandler) Create(c *gin.Context) {
+	userID := getUserID(c)
+
+	var req struct {
+		Name        string `json:"name" binding:"required,min=1,max=100"`
+		Description string `json:"description"`
+	}
+	if err := c.ShouldBindJSON(&req); err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
+		return
+	}
+
+	var g models.PersonaGroup
+	if database.IsSQLite() {
+		id := store.NewID()
+		_, err := database.DB.ExecContext(c.Request.Context(), `
+			INSERT INTO persona_groups (id, name, description, owner_id, scope)
+			VALUES (?, ?, ?, ?, 'personal')
+		`, id, strings.TrimSpace(req.Name), req.Description, userID)
+		if err != nil {
+			c.JSON(http.StatusInternalServerError, gin.H{"error": "failed to create group"})
+			return
+		}
+		database.DB.QueryRowContext(c.Request.Context(), `
+			SELECT id, name, description, owner_id, scope, team_id, created_at, updated_at
+			FROM persona_groups WHERE id = ?
+		`, id).Scan(&g.ID, &g.Name, &g.Description, &g.OwnerID,
+			&g.Scope, &g.TeamID, &g.CreatedAt, &g.UpdatedAt)
+	} else {
+		err := database.DB.QueryRowContext(c.Request.Context(), `
+			INSERT INTO persona_groups (name, description, owner_id, scope)
+			VALUES ($1, $2, $3, 'personal')
+			RETURNING id, name, description, owner_id, scope, team_id, created_at, updated_at
+		`, strings.TrimSpace(req.Name), req.Description, userID).Scan(
+			&g.ID, &g.Name, &g.Description, &g.OwnerID,
+			&g.Scope, &g.TeamID, &g.CreatedAt, &g.UpdatedAt)
+		if err != nil {
+			c.JSON(http.StatusInternalServerError, gin.H{"error": "failed to create group"})
+			return
+		}
+	}
+
+	g.Members = []models.PersonaGroupMember{}
+	c.JSON(http.StatusCreated, g)
+}
+
+// ── Update ──────────────────────────────────────
+
+func (h *PersonaGroupHandler) Update(c *gin.Context) {
+	userID := getUserID(c)
+	id := c.Param("id")
+
+	var req struct {
+		Name        *string `json:"name"`
+		Description *string `json:"description"`
+	}
+	if err := c.ShouldBindJSON(&req); err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
+		return
+	}
+
+	// Verify ownership
+	var ownerID string
+	err := database.DB.QueryRowContext(c.Request.Context(), database.Q(`
+		SELECT owner_id FROM persona_groups WHERE id = $1
+	`), id).Scan(&ownerID)
+	if err == sql.ErrNoRows {
+		c.JSON(http.StatusNotFound, gin.H{"error": "group not found"})
+		return
+	}
+	if ownerID != userID {
+		c.JSON(http.StatusForbidden, gin.H{"error": "not your group"})
+		return
+	}
+
+	if req.Name != nil {
+		database.DB.ExecContext(c.Request.Context(), database.Q(`
+			UPDATE persona_groups SET name = $1, updated_at = NOW() WHERE id = $2
+		`), strings.TrimSpace(*req.Name), id)
+	}
+	if req.Description != nil {
+		database.DB.ExecContext(c.Request.Context(), database.Q(`
+			UPDATE persona_groups SET description = $1, updated_at = NOW() WHERE id = $2
+		`), *req.Description, id)
+	}
+
+	c.JSON(http.StatusOK, gin.H{"ok": true})
+}
+
+// ── Delete ──────────────────────────────────────
+
+func (h *PersonaGroupHandler) Delete(c *gin.Context) {
+	userID := getUserID(c)
+	id := c.Param("id")
+
+	result, err := database.DB.ExecContext(c.Request.Context(), database.Q(`
+		DELETE FROM persona_groups WHERE id = $1 AND owner_id = $2
+	`), id, userID)
+	if err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": "delete failed"})
+		return
+	}
+	n, _ := result.RowsAffected()
+	if n == 0 {
+		c.JSON(http.StatusNotFound, gin.H{"error": "group not found"})
+		return
+	}
+	c.JSON(http.StatusOK, gin.H{"ok": true})
+}
+
+// ── Add Member ──────────────────────────────────
+
+func (h *PersonaGroupHandler) AddMember(c *gin.Context) {
+	userID := getUserID(c)
+	groupID := c.Param("id")
+
+	var req struct {
+		PersonaID string `json:"persona_id" binding:"required"`
+		IsLeader  bool   `json:"is_leader"`
+	}
+	if err := c.ShouldBindJSON(&req); err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
+		return
+	}
+
+	// Verify ownership
+	var ownerID string
+	err := database.DB.QueryRowContext(c.Request.Context(), database.Q(`
+		SELECT owner_id FROM persona_groups WHERE id = $1
+	`), groupID).Scan(&ownerID)
+	if err != nil || ownerID != userID {
+		c.JSON(http.StatusForbidden, gin.H{"error": "not your group"})
+		return
+	}
+
+	// If setting as leader, clear existing leader
+	if req.IsLeader {
+		database.DB.ExecContext(c.Request.Context(), database.Q(`
+			UPDATE persona_group_members SET is_leader = false WHERE group_id = $1
+		`), groupID)
+	}
+
+	if database.IsSQLite() {
+		id := store.NewID()
+		_, err = database.DB.ExecContext(c.Request.Context(), `
+			INSERT INTO persona_group_members (id, group_id, persona_id, is_leader)
+			VALUES (?, ?, ?, ?)
+			ON CONFLICT (group_id, persona_id) DO UPDATE SET is_leader = excluded.is_leader
+		`, id, groupID, req.PersonaID, req.IsLeader)
+	} else {
+		_, err = database.DB.ExecContext(c.Request.Context(), `
+			INSERT INTO persona_group_members (group_id, persona_id, is_leader)
+			VALUES ($1, $2, $3)
+			ON CONFLICT (group_id, persona_id) DO UPDATE SET is_leader = EXCLUDED.is_leader
+		`, groupID, req.PersonaID, req.IsLeader)
+	}
+	if err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": "failed to add member"})
+		return
+	}
+
+	c.JSON(http.StatusCreated, gin.H{"ok": true})
+}
+
+// ── Remove Member ───────────────────────────────
+
+func (h *PersonaGroupHandler) RemoveMember(c *gin.Context) {
+	userID := getUserID(c)
+	groupID := c.Param("id")
+	memberID := c.Param("memberId")
+
+	// Verify ownership
+	var ownerID string
+	err := database.DB.QueryRowContext(c.Request.Context(), database.Q(`
+		SELECT owner_id FROM persona_groups WHERE id = $1
+	`), groupID).Scan(&ownerID)
+	if err != nil || ownerID != userID {
+		c.JSON(http.StatusForbidden, gin.H{"error": "not your group"})
+		return
+	}
+
+	database.DB.ExecContext(c.Request.Context(), database.Q(`
+		DELETE FROM persona_group_members WHERE id = $1 AND group_id = $2
+	`), memberID, groupID)
+
+	c.JSON(http.StatusOK, gin.H{"ok": true})
+}
+
+// ── Helpers ─────────────────────────────────────
+
+func (h *PersonaGroupHandler) loadMembers(c *gin.Context, groupID string) []models.PersonaGroupMember {
+	rows, err := database.DB.QueryContext(c.Request.Context(), database.Q(`
+		SELECT pgm.id, pgm.group_id, pgm.persona_id, pgm.is_leader, pgm.sort_order,
+		       COALESCE(p.name, '') AS persona_name,
+		       COALESCE(p.handle, '') AS persona_handle,
+		       COALESCE(p.avatar, '') AS persona_avatar
+		FROM persona_group_members pgm
+		LEFT JOIN personas p ON p.id = pgm.persona_id
+		WHERE pgm.group_id = $1
+		ORDER BY pgm.is_leader DESC, pgm.sort_order, pgm.id
+	`), groupID)
+	if err != nil {
+		return []models.PersonaGroupMember{}
+	}
+	defer rows.Close()
+
+	members := []models.PersonaGroupMember{}
+	for rows.Next() {
+		var m models.PersonaGroupMember
+		if err := rows.Scan(&m.ID, &m.GroupID, &m.PersonaID, &m.IsLeader, &m.SortOrder,
+			&m.PersonaName, &m.PersonaHandle, &m.PersonaAvatar); err != nil {
+			continue
+		}
+		members = append(members, m)
+	}
+	return members
+}
--- a/server/handlers/presence.go
+++ b/server/handlers/presence.go
@@ -67,3 +67,50 @@ func PresenceQuery(c *gin.Context) {
 	}
 	c.JSON(http.StatusOK, gin.H{"presence": result})
 }
+
+// SearchUsers returns a lightweight list of approved users matching a query.
+// GET /api/v1/users/search?q=alice — matches against username and display_name.
+// Returns at most 20 results. Excludes the calling user.
+func SearchUsers(c *gin.Context) {
+	userID := getUserID(c)
+	q := strings.TrimSpace(c.Query("q"))
+
+	query := database.Q(`
+		SELECT id, username, COALESCE(display_name, '') AS display_name
+		FROM users
+		WHERE is_active = true AND id != $1
+	`)
+	args := []interface{}{userID}
+
+	if q != "" {
+		query += database.Q(` AND (LOWER(username) LIKE $2 OR LOWER(display_name) LIKE $3)`)
+		pattern := "%" + strings.ToLower(q) + "%"
+		args = append(args, pattern, pattern)
+	}
+
+	query += ` ORDER BY username LIMIT 20`
+
+	rows, err := database.DB.QueryContext(c.Request.Context(), query, args...)
+	if err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": "search failed"})
+		return
+	}
+	defer rows.Close()
+
+	type userResult struct {
+		ID          string `json:"id"`
+		Username    string `json:"username"`
+		DisplayName string `json:"display_name"`
+	}
+
+	results := []userResult{}
+	for rows.Next() {
+		var u userResult
+		if err := rows.Scan(&u.ID, &u.Username, &u.DisplayName); err != nil {
+			continue
+		}
+		results = append(results, u)
+	}
+
+	c.JSON(http.StatusOK, gin.H{"users": results})
+}
--- a/server/main.go
+++ b/server/main.go
@@ -376,6 +376,46 @@ func main() {
 			protected.GET("/channels/:id", channels.GetChannel)
 			protected.PUT("/channels/:id", channels.UpdateChannel)
 			protected.DELETE("/channels/:id", channels.DeleteChannel)
+			protected.POST("/channels/:id/mark-read", channels.MarkRead)
+
+			// Typing indicator broadcast (v0.23.2)
+			protected.POST("/channels/:id/typing", func(c *gin.Context) {
+				userID := c.GetString("user_id")
+				channelID := c.Param("id")
+				// Resolve display name
+				var displayName string
+				_ = database.DB.QueryRow(database.Q(`
+					SELECT COALESCE(display_name, username) FROM users WHERE id = $1
+				`), userID).Scan(&displayName)
+				if displayName == "" {
+					displayName = userID[:8]
+				}
+				// Broadcast to other user participants
+				pRows, err := database.DB.Query(database.Q(`
+					SELECT participant_id FROM channel_participants
+					WHERE channel_id = $1 AND participant_type = 'user' AND participant_id != $2
+				`), channelID, userID)
+				if err == nil {
+					defer pRows.Close()
+					payload, _ := json.Marshal(map[string]any{
+						"channel_id":   channelID,
+						"user_id":      userID,
+						"display_name": displayName,
+					})
+					evt := events.Event{
+						Label:   "typing.user",
+						Payload: payload,
+						Ts:      time.Now().UnixMilli(),
+					}
+					for pRows.Next() {
+						var pid string
+						if pRows.Scan(&pid) == nil {
+							hub.SendToUser(pid, evt)
+						}
+					}
+				}
+				c.JSON(200, gin.H{"ok": true})
+			})

 			// Chat Folders (v0.23.1)
 			folders := handlers.NewFolderHandler()
@@ -388,6 +428,19 @@ func main() {
 			protected.POST("/presence/heartbeat", handlers.PresenceHeartbeat)
 			protected.GET("/presence", handlers.PresenceQuery)

+			// User search (v0.23.2 — DM user picker)
+			protected.GET("/users/search", handlers.SearchUsers)
+
+			// Persona groups (v0.23.2 — roster templates for group chats)
+			pgH := handlers.NewPersonaGroupHandler()
+			protected.GET("/persona-groups", pgH.List)
+			protected.POST("/persona-groups", pgH.Create)
+			protected.GET("/persona-groups/:id", pgH.Get)
+			protected.PUT("/persona-groups/:id", pgH.Update)
+			protected.DELETE("/persona-groups/:id", pgH.Delete)
+			protected.POST("/persona-groups/:id/members", pgH.AddMember)
+			protected.DELETE("/persona-groups/:id/members/:memberId", pgH.RemoveMember)
+
 			// Channel models (v0.20.0 — multi-model @mention routing)
 			chModelH := handlers.NewChannelModelHandler(stores)
 			protected.GET("/channels/:id/models", chModelH.List)
@@ -802,6 +855,10 @@ func main() {
 			admin.POST("/storage/cleanup", fileAdm.CleanupOrphans)
 			admin.GET("/storage/extraction", fileAdm.ExtractionStatus)

+			// Archived channels (admin — v0.23.2)
+			admin.GET("/channels/archived", adm.ListArchivedChannels)
+			admin.DELETE("/channels/:id/purge", adm.PurgeChannel)
+
 			// Extensions (admin)
 			extAdm := handlers.NewExtensionHandler(stores)
 			admin.GET("/extensions", extAdm.AdminListExtensions)
--- a/server/pages/templates/surfaces/chat.html
+++ b/server/pages/templates/surfaces/chat.html
@@ -160,7 +160,10 @@ window.addEventListener('unhandledrejection', function(e) {
                            </button>
                        </div>
                    </div>
-                    <div class="sb-section-body" id="sbBodyChats">
+                    <div class="sb-section-body" id="sbBodyChats"
+                         ondragover="event.preventDefault();event.dataTransfer.dropEffect='move';this.classList.add('drag-over')"
+                         ondragleave="this.classList.remove('drag-over')"
+                         ondrop="onChatSectionDrop(event)">
                        {{/* Populated by UI.renderChatList() */}}
                    </div>
                </div>
@@ -264,6 +267,9 @@ window.addEventListener('unhandledrejection', function(e) {
                    </div>
                </div>

+                {{/* v0.23.2: Channel context banner — shown for DMs and named channels */}}
+                <div id="channelContextBanner" class="channel-context-banner" style="display:none;"></div>
+
                {{/* Messages */}}
                <div id="chatMessages" class="msg-container">
                    {{/* Populated by UI.renderMessages() */}}
--- a/server/pages/templates/surfaces/settings.html
+++ b/server/pages/templates/surfaces/settings.html
@@ -140,6 +140,10 @@
                </div>
                <div id="userAddPersonaForm" style="display:none;"></div>
                <div id="userPersonaList"><div class="settings-placeholder">Loading personas…</div></div>
+                {{else if eq .Section "models"}}
+                <div id="userModelList"><div class="settings-placeholder">Loading models…</div></div>
+                {{else if eq .Section "teams"}}
+                <div id="settingsDynamic"><div class="settings-placeholder">Loading teams…</div></div>
                {{else}}<div class="settings-placeholder" id="settingsDynamic">Loading…</div>
                {{end}}
            </div>
--- a/server/treepath/path.go
+++ b/server/treepath/path.go
@@ -25,6 +25,8 @@ type PathMessage struct {
 	SiblingIndex    int              `json:"sibling_index"`
 	ParticipantType string           `json:"participant_type,omitempty"`
 	ParticipantID   string           `json:"participant_id,omitempty"`
+	SenderName      *string          `json:"sender_name,omitempty"`
+	SenderAvatar    *string          `json:"sender_avatar,omitempty"`
 	CreatedAt       string           `json:"created_at"`
 }

@@ -159,5 +161,79 @@ func GetPathToLeaf(channelID, leafID string) ([]PathMessage, error) {
 		path[i].SiblingCount = GetSiblingCount(channelID, path[i].ParentID)
 	}

+	// v0.23.2: Resolve sender names and avatars
+	resolveSenderInfo(path)
+
 	return path, nil
 }
+
+// resolveSenderInfo batch-resolves sender_name and sender_avatar for path messages.
+func resolveSenderInfo(path []PathMessage) {
+	// Collect unique participant IDs by type
+	userIDs := map[string]bool{}
+	personaIDs := map[string]bool{}
+	for _, m := range path {
+		if m.ParticipantID == "" {
+			continue
+		}
+		switch m.ParticipantType {
+		case "user":
+			userIDs[m.ParticipantID] = true
+		case "persona":
+			personaIDs[m.ParticipantID] = true
+		}
+	}
+
+	// Resolve users
+	userNames := map[string]string{}
+	userAvatars := map[string]string{}
+	for uid := range userIDs {
+		var name, avatar sql.NullString
+		_ = database.DB.QueryRow(database.Q(`
+			SELECT COALESCE(display_name, username), avatar_url FROM users WHERE id = $1
+		`), uid).Scan(&name, &avatar)
+		if name.Valid {
+			userNames[uid] = name.String
+		}
+		if avatar.Valid {
+			userAvatars[uid] = avatar.String
+		}
+	}
+
+	// Resolve personas
+	personaNames := map[string]string{}
+	personaAvatars := map[string]string{}
+	for pid := range personaIDs {
+		var name, avatar sql.NullString
+		_ = database.DB.QueryRow(database.Q(`
+			SELECT name, avatar FROM personas WHERE id = $1
+		`), pid).Scan(&name, &avatar)
+		if name.Valid {
+			personaNames[pid] = name.String
+		}
+		if avatar.Valid {
+			personaAvatars[pid] = avatar.String
+		}
+	}
+
+	// Apply to path
+	for i := range path {
+		pid := path[i].ParticipantID
+		switch path[i].ParticipantType {
+		case "user":
+			if n, ok := userNames[pid]; ok {
+				path[i].SenderName = &n
+			}
+			if a, ok := userAvatars[pid]; ok && a != "" {
+				path[i].SenderAvatar = &a
+			}
+		case "persona":
+			if n, ok := personaNames[pid]; ok {
+				path[i].SenderName = &n
+			}
+			if a, ok := personaAvatars[pid]; ok && a != "" {
+				path[i].SenderAvatar = &a
+			}
+		}
+	}
+}
--- a/src/css/channel-models.css
+++ b/src/css/channel-models.css
@@ -191,6 +191,11 @@
    border-radius: 4px;
    font-size: 0.92em;
 }
+/* v0.23.2: User mention pill — teal to distinguish from AI mentions */
+.mention-pill.mention-user {
+    color: #2dd4bf;
+    background: rgba(45,212,191,0.12);
+}

 /* ── Model Attribution (multi-model messages) ─ */

--- a/src/css/chat.css
+++ b/src/css/chat.css
@@ -32,6 +32,48 @@
    display: inline-flex; align-items: center; gap: 4px;
 }

+/* v0.23.2: Channel context banner */
+.channel-context-banner {
+    padding: 6px 16px;
+    font-size: 12px;
+    color: var(--text-3);
+    background: var(--bg-raised);
+    border-bottom: 1px solid var(--border);
+    display: flex;
+    align-items: center;
+    gap: 8px;
+    flex-shrink: 0;
+}
+.channel-context-banner .ctx-mode {
+    font-family: var(--mono);
+    font-size: 11px;
+    padding: 1px 6px;
+    border-radius: 3px;
+    background: var(--bg-surface);
+    color: var(--text-2);
+}
+.channel-context-banner .ctx-mode-btn {
+    cursor: pointer; border: 1px solid var(--border);
+    transition: background 0.15s;
+}
+.channel-context-banner .ctx-mode-btn:hover {
+    background: var(--bg-hover); color: var(--text);
+}
+.channel-context-banner .ctx-topic {
+    color: var(--text-2); font-size: 12px;
+}
+.channel-context-banner .ctx-hint {
+    color: var(--text-3);
+    font-style: italic;
+}
+.ctx-participants-btn {
+    margin-left: auto;
+    background: none; border: 1px solid var(--border); border-radius: 4px;
+    color: var(--text-2); font-size: 11px; padding: 2px 8px; cursor: pointer;
+}
+.ctx-participants-btn:hover { background: var(--bg-hover); color: var(--text); }
+.hover-bg:hover { background: var(--bg-hover); }
+
 /* Message container (scrollable) */
 .msg-container {
    flex: 1; overflow-y: auto; scroll-behavior: smooth;
@@ -171,6 +213,16 @@
 .message.user .msg-avatar { background: var(--accent-dim); }
 .message.assistant .msg-avatar { background: var(--bg-raised); }

+/* Other human's messages — left-aligned like assistant, teal accent */
+.message.other-user .msg-body {
+    background: var(--bg-surface);
+    border: 1px solid var(--border);
+    border-radius: 16px 16px 16px 4px;
+    padding: 10px 14px;
+}
+.message.other-user .msg-role { color: #2dd4bf; }
+.message.other-user .msg-avatar { background: rgba(45,212,191,0.12); color: #2dd4bf; }
+
 .msg-body { flex: 1; min-width: 0; }
 .msg-head { display: flex; align-items: center; gap: 8px; margin-bottom: 4px; }
 .msg-role { font-size: 13px; font-weight: 600; }
--- a/src/css/surfaces.css
+++ b/src/css/surfaces.css
@@ -705,6 +705,14 @@
 .sb-channel-item.active { background: var(--bg-raised); color: var(--text); }
 .sidebar.collapsed .sb-channel-item { justify-content: center; padding: 5px 0; margin: 0 6px; }

+.sb-ch-menu {
+    visibility: hidden; background: none; border: none; color: var(--text-3); cursor: pointer;
+    font-size: 14px; padding: 0 4px; line-height: 1; border-radius: 3px; margin-left: auto;
+}
+.sb-ch-menu:hover { color: var(--text); background: var(--bg-hover); }
+.sb-channel-item:hover .sb-ch-menu { visibility: visible; }
+.sidebar.collapsed .sb-ch-menu { display: none; }
+
 .sb-ch-icon { color: var(--text-3); flex-shrink: 0; display: flex; }
 .sb-ch-name { flex: 1; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
 .sidebar.collapsed .sb-ch-name { display: none; }
@@ -731,14 +739,15 @@
 /* ── Chats section folder items ── */

 .sb-folder-group { margin-bottom: 1px; }
+.sb-folder-group.drag-over .sb-folder-header { background: var(--accent-dim); }
 .sb-folder-name { flex: 1; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
 .sb-folder-menu {
-    display: none; background: none; border: none; cursor: pointer;
+    visibility: hidden; background: none; border: none; cursor: pointer;
    color: var(--text-3); font-size: 14px; padding: 0 2px; line-height: 1;
    flex-shrink: 0; border-radius: 3px;
 }
 .sb-folder-menu:hover { color: var(--text); background: var(--bg-hover); }
-.sb-folder-header:hover .sb-folder-menu { display: block; }
+.sb-folder-header:hover .sb-folder-menu { visibility: visible; }
 .sb-folder-empty { padding: 4px 14px 6px 28px; font-size: 11px; color: var(--text-3); font-style: italic; }

 .sb-folder-header {
@@ -756,7 +765,13 @@
 }
 .sb-folder-header:hover { background: var(--bg-hover); color: var(--text-2); }

-.sb-folder-arrow { margin-left: auto; font-size: 9px; }
+.sb-folder-arrow { font-size: 9px; flex-shrink: 0; width: 12px; text-align: center; }
+
+/* v0.23.2: Drop zone for chats section */
+#sbBodyChats.drag-over { outline: 2px dashed var(--accent); outline-offset: -2px; border-radius: 4px; }
+.sb-unfiled-zone { min-height: 30px; border-radius: 4px; margin-top: 2px; }
+.sb-unfiled-zone.drag-over { outline: 2px dashed var(--accent); outline-offset: -2px; }
+.sb-unfiled-hint { padding: 6px 14px; font-size: 11px; color: var(--text-3); font-style: italic; }

 /* Indented chat items inside folders */
 .chat-item.indented { padding-left: 28px; }
--- a/src/js/admin-scaffold.js
+++ b/src/js/admin-scaffold.js
@@ -220,6 +220,13 @@
    SCAFFOLDING.stats =
        '<div id="adminStats" class="stat-cards-grid"><div class="loading">Loading...</div></div>';

+    SCAFFOLDING.channels =
+        '<div class="stat-cards-grid" style="margin-bottom:16px">' +
+          '<div class="stat-card"><div class="stat-value" id="adminArchivedCount">—</div><div class="stat-label">Archived</div></div>' +
+          '<div class="stat-card"><div class="stat-value" id="adminRetentionMode">—</div><div class="stat-label">Retention Mode</div></div>' +
+        '</div>' +
+        '<div id="adminArchivedList" class="admin-list"><div class="loading">Loading...</div></div>';
+

    // === Add button actions ==============================================

@@ -272,7 +279,7 @@
            users:'people', teams:'people', groups:'people',
            providers:'ai', models:'ai', personas:'ai', roles:'ai', knowledgeBases:'ai', memory:'ai',
            health:'routing', routing:'routing', capabilities:'routing',
-            settings:'system', storage:'system', extensions:'system',
+            settings:'system', storage:'system', extensions:'system', channels:'system',
            usage:'monitoring', audit:'monitoring', stats:'monitoring',
        };
        var cat = catMap[section] || 'people';
@@ -280,7 +287,7 @@
            people: [{id:'users',l:'Users'},{id:'teams',l:'Teams'},{id:'groups',l:'Groups'}],
            ai: [{id:'providers',l:'Providers'},{id:'models',l:'Models'},{id:'personas',l:'Personas'},{id:'roles',l:'Roles'},{id:'knowledgeBases',l:'Knowledge'},{id:'memory',l:'Memory'}],
            routing: [{id:'health',l:'Health'},{id:'routing',l:'Routing'},{id:'capabilities',l:'Capabilities'}],
-            system: [{id:'settings',l:'Settings'},{id:'storage',l:'Storage'},{id:'extensions',l:'Extensions'}],
+            system: [{id:'settings',l:'Settings'},{id:'storage',l:'Storage'},{id:'extensions',l:'Extensions'},{id:'channels',l:'Channels'}],
            monitoring: [{id:'usage',l:'Usage'},{id:'audit',l:'Audit'},{id:'stats',l:'Stats'}],
        };

--- a/src/js/api.js
+++ b/src/js/api.js
@@ -187,6 +187,7 @@ const API = {
    updateChannel(id, updates) { return this._put(`/api/v1/channels/${id}`, updates); },
    generateTitle(id) { return this._post(`/api/v1/channels/${id}/generate-title`, {}); },
    deleteChannel(id) { return this._del(`/api/v1/channels/${id}`); },
+    markRead(id) { return this._post(`/api/v1/channels/${id}/mark-read`, {}); },

    // Channel models (v0.20.0 — multi-model @mention routing)
    listChannelModels(channelId) { return this._get(`/api/v1/channels/${channelId}/models`); },
--- a/src/js/app-state.js
+++ b/src/js/app-state.js
@@ -7,7 +7,6 @@

 const App = {
    chats: [],
-    currentChatId: null,
    models: [],
    hiddenModels: new Set(),
    isGenerating: false,
@@ -21,12 +20,32 @@ const App = {
    collapsedProjects: {},
    activeProjectId: null,
    showArchivedProjects: false,
+    // v0.23.2: Unified active conversation
+    activeConversation: null,  // { id, type } where type = direct|dm|group|channel
    // v0.23.1: Multi-user
-    channels: [],           // DMs + named channels
-    currentChannelId: null,
+    channels: [],           // DMs + named channels (sidebar display data)
    folders: [],            // chat folders (user-scoped)
    collapsedFolders: {},
    presence: {},           // { userId: 'online' | 'offline' }
+    users: [],              // v0.23.2: [{id, username, displayName}] for @mention autocomplete
+
+    /** Get active conversation ID (shorthand). */
+    get activeId() { return this.activeConversation?.id || null; },
+
+    /** Get active conversation type. */
+    get activeType() { return this.activeConversation?.type || null; },
+
+    /** Set the active conversation. Clears if id is null. */
+    setActive(id, type) {
+        this.activeConversation = id ? { id, type: type || 'direct' } : null;
+    },
+
+    /** Find the active conversation's chat object (with cached messages). */
+    getActiveChat() {
+        const id = this.activeConversation?.id;
+        if (!id) return null;
+        return this.chats.find(c => c.id === id) || null;
+    },

    findModel(id) {
        if (!id) return null;
--- a/src/js/app.js
+++ b/src/js/app.js
@@ -93,6 +93,9 @@ async function startApp() {
        UI.updateCapabilityBadges();
    }

+    // v0.23.2: Load user list for @mention autocomplete
+    await loadUsers();
+
    // Guard: if token was invalidated during startup (401 → refresh fail → clearTokens),
    // kick back to login instead of rendering a broken UI.
    if (!API.isAuthed) {
@@ -103,6 +106,16 @@ async function startApp() {

    await initBanners();
    initFiles();
+
+    // v0.23.2: Create primary ChatPane instance from server-rendered mount points
+    if (typeof ChatPane !== 'undefined') {
+        ChatPane.primary = ChatPane.create({
+            id: 'main',
+            messagesEl: document.getElementById('chatMessages'),
+            inputEl: document.getElementById('chatInputBar'),
+            standalone: false,
+        });
+    }
    if (typeof ToolsToggle !== 'undefined') ToolsToggle.init();
    if (typeof REPL !== 'undefined') REPL.init();  // v0.21.3: admin-gated REPL tab
    if (typeof KnowledgeUI !== 'undefined') {
@@ -115,16 +128,25 @@ async function startApp() {
    UI.restoreSidebarSections();
    UI.updateModelSelector();

-    // Restore last-active chat from sessionStorage
+    // Restore last-active conversation from sessionStorage
    try {
-        const savedChat = sessionStorage.getItem('cs-active-chat');
-        if (savedChat && App.chats.some(c => c.id === savedChat)) {
-            selectChat(savedChat);
+        const saved = sessionStorage.getItem('cs-active-conversation');
+        if (saved) {
+            const ac = JSON.parse(saved);
+            if (ac?.id) {
+                const inChats = App.chats.some(c => c.id === ac.id);
+                const inChannels = (App.channels || []).some(c => c.id === ac.id);
+                if (inChats) {
+                    selectChat(ac.id);
+                } else if (inChannels) {
+                    selectChannel(ac.id);
+                }
+            }
        }
    } catch (_) {}

-    // If no chat was restored, show the welcome/empty state
-    if (!App.currentChatId) {
+    // If no conversation was restored, show the welcome/empty state
+    if (!App.activeId) {
        UI.showEmptyState();
    }

@@ -234,7 +256,7 @@ async function handleLogout() {
    Events.clear();
    await API.logout();
    App.chats = [];
-    App.currentChatId = null;
+    App.setActive(null);
    location.reload();
 }

--- a/src/js/channel-models.js
+++ b/src/js/channel-models.js
@@ -206,22 +206,41 @@ const ChannelModels = {

        // Build match list from ALL enabled models + personas (not just roster)
        const allModels = (App.models || []).filter(m => !m.hidden);
-        const matches = allModels.filter(m => {
-            // Match against persona handle
+        const modelMatches = allModels.filter(m => {
            const handle = (m.personaHandle || '').toLowerCase().replace(/-/g, ' ');
-            // Match against model ID
            const modelId = (m.baseModelId || m.id || '').toLowerCase().replace(/-/g, ' ');
-            // Match against display name
            const name = (m.name || '').toLowerCase().replace(/-/g, ' ');
            const firstName = name.split(' ')[0] || '';

-            if (partial.length === 0) return true; // show all on bare @
+            if (partial.length === 0) return true;
            return handle.startsWith(partial)
                || modelId.startsWith(partial)
                || name.startsWith(partial)
                || firstName.startsWith(partial);
        });

+        // v0.23.2: Include users in autocomplete (after personas, before models)
+        const userMatches = (App.users || []).filter(u => {
+            const uname = u.username.toLowerCase();
+            const dname = (u.displayName || '').toLowerCase();
+            if (partial.length === 0) return true;
+            return uname.startsWith(partial) || dname.startsWith(partial);
+        }).map(u => ({
+            id: u.username,
+            name: u.displayName || u.username,
+            baseModelId: u.username,
+            isPersona: false,
+            isUser: true,
+            personaHandle: null,
+            personaAvatar: null,
+            provider: '',
+        }));
+
+        // Resolution order: personas first, then users, then models
+        const personas = modelMatches.filter(m => m.isPersona);
+        const models = modelMatches.filter(m => !m.isPersona);
+        const matches = [...personas, ...userMatches, ...models];
+
        if (matches.length === 0) { this.hideAutocomplete(); return; }
        // Cap at 10 to keep dropdown manageable
        this.showAutocomplete(inputEl, atIdx, cursorPos, matches.slice(0, 10));
@@ -253,13 +272,17 @@ const ChannelModels = {
                ? `<img src="${esc(m.personaAvatar)}" class="mention-ac-avatar" alt="">`
                : m.isPersona
                    ? `<span class="mention-ac-avatar mention-ac-avatar-fallback">⚡</span>`
+                    : m.isUser
+                        ? `<span class="mention-ac-avatar mention-ac-avatar-fallback mention-ac-user">👤</span>`
                        : `<span class="mention-ac-avatar mention-ac-avatar-fallback">🤖</span>`;

            const handleText = m.isPersona && m.personaHandle
                ? `@${esc(m.personaHandle)}`
+                : m.isUser
+                    ? `@${esc(m.baseModelId)}`
                    : `@${esc(m.baseModelId || m.id)}`;

-            const providerHint = m.provider ? esc(m.provider) : '';
+            const providerHint = m.isUser ? 'user' : (m.provider ? esc(m.provider) : '');

            item.innerHTML = `${avatar}<div class="mention-ac-info"><span class="mention-ac-name">${esc(m.name || m.id)}</span><span class="mention-ac-handle">${handleText}</span></div><span class="mention-ac-model">${providerHint}</span>`;
            item.addEventListener('click', () => {
--- a/src/js/chat.js
+++ b/src/js/chat.js
@@ -83,6 +83,8 @@ const ChatInput = {
                    updateInputTokens();
                    // @mention autocomplete (v0.20.0)
                    if (typeof ChannelModels !== 'undefined') ChannelModels.onInput(ChatInput);
+                    // v0.23.2: Typing indicator for multi-user channels
+                    _emitTyping();
                },
                maxHeight: 200,
            });
@@ -108,15 +110,30 @@ const ChatInput = {
                updateInputTokens();
                // @mention autocomplete (v0.20.0)
                if (typeof ChannelModels !== 'undefined') ChannelModels.onInput(this);
+                // v0.23.2: Typing indicator
+                _emitTyping();
            });
        }
    },
 };

+// v0.23.2: Debounced typing indicator for multi-user channels
+let _typingTimer = null;
+function _emitTyping() {
+    if (!App.activeId) return;
+    // Only emit for multi-user conversation types
+    const type = App.activeConversation?.type;
+    if (type !== 'dm' && type !== 'channel' && type !== 'group') return;
+    // Debounce: emit at most once every 3s
+    if (_typingTimer) return;
+    _typingTimer = setTimeout(() => { _typingTimer = null; }, 3000);
+    API._post(`/api/v1/channels/${App.activeId}/typing`, {}).catch(() => {});
+}
+
 // ── Summarize & Continue ──────────────────

 async function summarizeAndContinue() {
-    const channelId = App.currentChatId;
+    const channelId = App.activeId;
    if (!channelId) return;

    const btn = document.getElementById('summarizeBtn');
@@ -145,6 +162,10 @@ async function summarizeAndContinue() {
                metadata: m.metadata || null,
                siblingCount: m.sibling_count || 1,
                siblingIndex: m.sibling_index || 0,
+                participant_type: m.participant_type || null,
+                participant_id: m.participant_id || null,
+                sender_name: m.sender_name || null,
+                sender_avatar: m.sender_avatar || null,
            }));
            UI.renderMessages(chat.messages);
            updateContextWarning(); updateChatTokenCount();
@@ -164,7 +185,7 @@ async function summarizeAndContinue() {
 // ── Per-Channel Auto-Compaction Toggle ──────

 async function toggleChannelAutoCompact(enabled) {
-    const chatId = App.currentChatId;
+    const chatId = App.activeId;
    if (!chatId) return;
    const chat = App.chats.find(c => c.id === chatId);
    if (!chat) return;
@@ -193,6 +214,7 @@ async function loadChats() {
            model: c.model || '',
            messageCount: c.message_count || 0,
            projectId: c.project_id || null,
+            folderId: c.folder || null,
            workspace_id: c.workspace_id || null,
            messages: [],
            updatedAt: c.updated_at,
@@ -206,16 +228,17 @@ async function loadChats() {

 async function selectChat(chatId) {
    clearStaged();  // Discard any staged files from previous chat
-    App.currentChatId = chatId;
-    try { sessionStorage.setItem('cs-active-chat', chatId); } catch (_) {}
+    const chat = App.chats.find(c => c.id === chatId);
+    App.setActive(chatId, chat?.type || 'direct');
+    try { sessionStorage.setItem('cs-active-conversation', JSON.stringify(App.activeConversation)); } catch (_) {}
    UI.renderChatList();
+    UI.renderChannelsSection();
    if (window.innerWidth <= 768) {
        document.getElementById('sidebar').classList.add('collapsed');
        const ov = document.getElementById('sidebarOverlay');
        if (ov) ov.style.display = 'none';
    }

-    const chat = App.chats.find(c => c.id === chatId);
    if (!chat) return;

    if (chat.messages.length === 0 && chat.messageCount > 0) {
@@ -233,6 +256,10 @@ async function selectChat(chatId) {
                metadata: m.metadata || null,
                siblingCount: m.sibling_count || 1,
                siblingIndex: m.sibling_index || 0,
+                participant_type: m.participant_type || null,
+                participant_id: m.participant_id || null,
+                sender_name: m.sender_name || null,
+                sender_avatar: m.sender_avatar || null,
            }));
        } catch (e) {
            console.error('Failed to load messages:', e.message);
@@ -250,6 +277,7 @@ async function selectChat(chatId) {
    await loadChannelFiles(chatId);

    UI.renderMessages(chat.messages);
+    UI.updateContextBanner();
    UI.showRegenerate(chat.messages.some(m => m.role === 'assistant'));
    Tokens._warningDismissed = false;
    updateContextWarning(); updateChatTokenCount();
@@ -264,6 +292,9 @@ async function selectChat(chatId) {

    // Update browser URL to reflect selected chat
    window.history.replaceState(null, '', `${window.__BASE__ || ''}/chat/${chatId}`);
+
+    // v0.23.2: Mark as read (non-blocking)
+    API.markRead(chatId).catch(() => {});
 }

 // ── Chat Header Token Count ──────────────────
@@ -271,7 +302,7 @@ async function selectChat(chatId) {
 function updateChatTokenCount() {
    const el = document.getElementById('chatTokenCount');
    if (!el) return;
-    const chat = App.chats.find(c => c.id === App.currentChatId);
+    const chat = App.getActiveChat();
    if (!chat || !chat.messages.length) { el.textContent = ''; return; }

    const tokens = Tokens.estimateConversation(chat.messages, App.settings?.systemPrompt);
@@ -379,8 +410,9 @@ function _cleanStaleChatModel(chatId) {

 async function newChat() {
    clearStaged();  // Discard any staged files
-    App.currentChatId = null;
+    App.setActive(null);
    UI.renderChatList();
+    UI.renderChannelsSection();
    UI.showEmptyState();
    UI.showRegenerate(false);
    Tokens._warningDismissed = false;
@@ -492,7 +524,7 @@ async function newGroupChat() {
                }

                App.chats.unshift(chat);
-                App.currentChatId = chat.id;
+                App.setActive(chat.id, 'group');
                UI.renderChatList();
                Events.emit('chat.created', { chatId: chat.id, projectId: null }, { localOnly: true });
                window.history.replaceState(null, '', `${window.__BASE__ || ''}/chat/${chat.id}`);
@@ -526,7 +558,7 @@ async function deleteChat(chatId) {
            delete map[chatId];
            localStorage.setItem('cs-chat-models', JSON.stringify(map));
        } catch (e) { /* */ }
-        if (App.currentChatId === chatId) { clearPreview(); newChat(); }
+        if (App.activeId === chatId) { clearPreview(); newChat(); }
        UI.renderChatList();
    } catch (e) { UI.toast('Failed to delete: ' + e.message, 'error'); }
 }
@@ -634,7 +666,7 @@ async function sendMessage() {
    const model = modelInfo?.baseModelId || selectedId;
    const personaId = modelInfo?.isPersona ? modelInfo.personaId : null;

-    if (!App.currentChatId) {
+    if (!App.activeId) {
        try {
            const title = text.slice(0, 50) + (text.length > 50 ? '...' : '');
            const resp = await API.createChannel(title, model, App.settings.systemPrompt, 'direct');
@@ -647,7 +679,7 @@ async function sendMessage() {
                } catch (_) { /* best effort — chat still works without project */ }
            }
            App.chats.unshift(chat);
-            App.currentChatId = chat.id;
+            App.setActive(chat.id, 'direct');
            UI.renderChatList();
            // Notify surfaces about new chat creation (v0.21.6)
            Events.emit('chat.created', { chatId: chat.id, projectId: chat.projectId || null }, { localOnly: true });
@@ -655,7 +687,7 @@ async function sendMessage() {
        } catch (e) { UI.toast('Failed to create chat: ' + e.message, 'error'); return; }
    }

-    const chat = App.chats.find(c => c.id === App.currentChatId);
+    const chat = App.getActiveChat();
    if (!chat) return;

    // Optimistic: show user message immediately
@@ -671,8 +703,20 @@ async function sendMessage() {
    UI.setGenerating(true);

    try {
-        const resp = await API.streamCompletion(App.currentChatId, text, model, App.abortController.signal, modelInfo?.configId, personaId, fileIds,
+        const resp = await API.streamCompletion(App.activeId, text, model, App.abortController.signal, modelInfo?.configId, personaId, fileIds,
            typeof ToolsToggle !== 'undefined' ? ToolsToggle.getDisabledTools() : []);
+
+        // v0.23.2: Non-streaming response (DM with mention_only, no @mention)
+        const ct = (resp.headers.get('content-type') || '').toLowerCase();
+        if (ct.includes('application/json')) {
+            const data = await resp.json();
+            if (data.ai_skipped) {
+                // Message was persisted server-side; reload to get proper IDs
+                await reloadActivePath();
+                return;
+            }
+        }
+
        await UI.streamResponse(resp, chat.messages, modelInfo?.name);

        // Reload active path from server to get proper IDs and sibling metadata
@@ -680,11 +724,11 @@ async function sendMessage() {
        UI.showRegenerate(true);

        // Persist the model/persona selection for this chat
-        _saveChatModel(App.currentChatId);
+        _saveChatModel(App.activeId);

        // Auto-name: title the chat after first assistant response (v0.17.0)
        if (chat.messages.length <= 3) {
-            autoNameChat(App.currentChatId, chat);
+            autoNameChat(App.activeId, chat);
        }
    } catch (e) {
        if (e.name === 'AbortError') {
@@ -717,12 +761,12 @@ function stopGeneration() { if (App.abortController) App.abortController.abort()
 // ── Reload Active Path from Server ──────────

 async function reloadActivePath() {
-    if (!App.currentChatId) return;
-    const chat = App.chats.find(c => c.id === App.currentChatId);
+    if (!App.activeId) return;
+    const chat = App.getActiveChat();
    if (!chat) return;

    try {
-        const resp = await API.getActivePath(App.currentChatId);
+        const resp = await API.getActivePath(App.activeId);
        chat.messages = (resp.path || []).map(m => ({
            id: m.id,
            parent_id: m.parent_id || null,
@@ -735,9 +779,13 @@ async function reloadActivePath() {
            metadata: m.metadata || null,
            siblingCount: m.sibling_count || 1,
            siblingIndex: m.sibling_index || 0,
+                participant_type: m.participant_type || null,
+                participant_id: m.participant_id || null,
+                sender_name: m.sender_name || null,
+                sender_avatar: m.sender_avatar || null,
        }));
        chat.messageCount = chat.messages.length;
-        await loadChannelFiles(App.currentChatId);
+        await loadChannelFiles(App.activeId);
        UI.renderMessages(chat.messages);
        updateContextWarning(); updateChatTokenCount();
    } catch (e) {
@@ -748,7 +796,7 @@ async function reloadActivePath() {
 // ── Regenerate (tree-aware: creates sibling) ─

 async function regenerateMessage(messageId) {
-    if (App.isGenerating || !App.currentChatId) return;
+    if (App.isGenerating || !App.activeId) return;

    const selectedId = UI.getModelValue();
    const modelInfo = App.findModel(selectedId);
@@ -758,7 +806,7 @@ async function regenerateMessage(messageId) {
    // Truncate display to the parent of the message being regenerated.
    // This makes the stream appear in the correct position — as a fresh
    // response to the parent user message, not appended at the bottom.
-    const chat = App.chats.find(c => c.id === App.currentChatId);
+    const chat = App.getActiveChat();
    if (chat) {
        const msgIdx = chat.messages.findIndex(m => m.id === messageId);
        if (msgIdx > 0) {
@@ -773,7 +821,7 @@ async function regenerateMessage(messageId) {

    try {
        const resp = await API.streamRegenerate(
-            App.currentChatId, messageId, App.abortController.signal,
+            App.activeId, messageId, App.abortController.signal,
            model, personaId, modelInfo?.configId,
            typeof ToolsToggle !== 'undefined' ? ToolsToggle.getDisabledTools() : []
        );
@@ -803,8 +851,8 @@ async function regenerateMessage(messageId) {

 // Legacy: bottom-bar regenerate button targets the last assistant message
 async function regenerate() {
-    if (App.isGenerating || !App.currentChatId) return;
-    const chat = App.chats.find(c => c.id === App.currentChatId);
+    if (App.isGenerating || !App.activeId) return;
+    const chat = App.getActiveChat();
    if (!chat || chat.messages.length === 0) return;

    // Find the last assistant message with an ID
@@ -819,9 +867,9 @@ async function regenerate() {
 // ── Edit Message (creates sibling, triggers completion) ──

 async function editMessage(messageId) {
-    if (App.isGenerating || !App.currentChatId) return;
+    if (App.isGenerating || !App.activeId) return;

-    const chat = App.chats.find(c => c.id === App.currentChatId);
+    const chat = App.getActiveChat();
    if (!chat) return;

    const msg = chat.messages.find(m => m.id === messageId);
@@ -832,7 +880,7 @@ async function editMessage(messageId) {
 }

 async function submitEdit(messageId, newContent) {
-    if (App.isGenerating || !App.currentChatId) return;
+    if (App.isGenerating || !App.activeId) return;
    if (!newContent.trim()) return;

    const selectedId = UI.getModelValue();
@@ -845,10 +893,10 @@ async function submitEdit(messageId, newContent) {
    UI.setGenerating(true);

    try {
-        const chat = App.chats.find(c => c.id === App.currentChatId);
+        const chat = App.getActiveChat();

        // Step 1: Create sibling user message via edit endpoint
-        const editResp = await API.editMessage(App.currentChatId, messageId, newContent.trim());
+        const editResp = await API.editMessage(App.activeId, messageId, newContent.trim());

        // Step 2: Reload path to show the new edited message
        await reloadActivePath();
@@ -858,7 +906,7 @@ async function submitEdit(messageId, newContent) {
        // a child response, not a sibling). This avoids the duplicate user
        // message that streamCompletion would create.
        const resp = await API.streamRegenerate(
-            App.currentChatId, editResp.id, App.abortController.signal,
+            App.activeId, editResp.id, App.abortController.signal,
            model, personaId, modelInfo?.configId,
            typeof ToolsToggle !== 'undefined' ? ToolsToggle.getDisabledTools() : []
        );
@@ -885,18 +933,18 @@ async function submitEdit(messageId, newContent) {

 function cancelEdit() {
    // Re-render to remove the edit form
-    const chat = App.chats.find(c => c.id === App.currentChatId);
+    const chat = App.getActiveChat();
    if (chat) UI.renderMessages(chat.messages);
 }

 // ── Switch Branch (sibling navigation) ──────

 async function switchSibling(messageId, direction) {
-    if (App.isGenerating || !App.currentChatId) return;
+    if (App.isGenerating || !App.activeId) return;

    try {
        // Get siblings for this message
-        const data = await API.listSiblings(App.currentChatId, messageId);
+        const data = await API.listSiblings(App.activeId, messageId);
        const siblings = data.siblings || [];
        const currentIdx = data.current_index ?? 0;

@@ -906,10 +954,10 @@ async function switchSibling(messageId, direction) {
        const targetSibling = siblings[targetIdx];

        // Update cursor to the target sibling (backend walks to leaf)
-        const resp = await API.updateCursor(App.currentChatId, targetSibling.id);
+        const resp = await API.updateCursor(App.activeId, targetSibling.id);

        // Update local state with the new path
-        const chat = App.chats.find(c => c.id === App.currentChatId);
+        const chat = App.getActiveChat();
        if (chat && resp.path) {
            chat.messages = resp.path.map(m => ({
                id: m.id,
@@ -923,6 +971,10 @@ async function switchSibling(messageId, direction) {
                metadata: m.metadata || null,
                siblingCount: m.sibling_count || 1,
                siblingIndex: m.sibling_index || 0,
+                participant_type: m.participant_type || null,
+                participant_id: m.participant_id || null,
+                sender_name: m.sender_name || null,
+                sender_avatar: m.sender_avatar || null,
            }));
            chat.messageCount = chat.messages.length;
            UI.renderMessages(chat.messages);
@@ -997,7 +1049,26 @@ function _initChatListeners() {
    // runs server-side and delivers the result via WS, not SSE.
    Events.on('message.created', (payload) => {
        if (!payload || !payload.channel_id) return;
-        if (payload.channel_id !== App.currentChatId) return;
+
+        // v0.23.2: If this channel isn't in our sidebar yet, fetch and add it
+        const knownChannel = (App.channels || []).some(c => c.id === payload.channel_id);
+        const knownChat = App.chats.some(c => c.id === payload.channel_id);
+        if (!knownChannel && !knownChat) {
+            // New channel we're a participant in — reload channels sidebar
+            if (typeof loadChannels === 'function') loadChannels();
+            UI.toast(`New message from ${payload.display_name || payload.user_id?.slice(0, 8) || 'someone'}`, 'info');
+            return;
+        }
+
+        // If it's a channel/DM we know but it's not the active one, bump unread
+        if (payload.channel_id !== App.activeId) {
+            const ch = (App.channels || []).find(c => c.id === payload.channel_id);
+            if (ch) {
+                ch.unread = (ch.unread || 0) + 1;
+                if (typeof UI !== 'undefined') UI.renderChannelsSection();
+            }
+            return;
+        }

        const chat = App.chats.find(c => c.id === payload.channel_id);
        if (!chat) return;
@@ -1021,16 +1092,18 @@ function _initChatListeners() {

        // Remove typing indicator and re-render
        document.getElementById('typingIndicator')?.remove();
+        document.getElementById('userTypingIndicator')?.remove();
        UI.renderMessages(chat.messages);
    });

    // Typing indicators from persona chain activity
    Events.on('typing.start', (payload) => {
-        if (!payload || payload.channel_id !== App.currentChatId) return;
+        if (!payload || payload.channel_id !== App.activeId) return;
        if (payload.participant_type !== 'persona') return;

        // Show typing indicator with persona name
        document.getElementById('typingIndicator')?.remove();
+        document.getElementById('userTypingIndicator')?.remove();
        const container = document.getElementById('chatMessages');
        if (!container) return;
        const typing = document.createElement('div');
@@ -1047,8 +1120,63 @@ function _initChatListeners() {
    });

    Events.on('typing.stop', (payload) => {
-        if (!payload || payload.channel_id !== App.currentChatId) return;
+        if (!payload || payload.channel_id !== App.activeId) return;
        document.getElementById('typingIndicator')?.remove();
+        document.getElementById('userTypingIndicator')?.remove();
+    });
+
+    // v0.23.2: Human typing indicator from other participants
+    Events.on('typing.user', (payload) => {
+        if (!payload || payload.channel_id !== App.activeId) return;
+        if (payload.user_id === API.user?.id) return; // ignore self
+
+        // Show or refresh typing indicator
+        let typing = document.getElementById('userTypingIndicator');
+        if (!typing) {
+            const container = document.getElementById('chatMessages');
+            if (!container) return;
+            typing = document.createElement('div');
+            typing.id = 'userTypingIndicator';
+            typing.className = 'message other-user';
+            container.appendChild(typing);
+        }
+        const name = payload.display_name || 'Someone';
+        typing.innerHTML = `
+            <div class="msg-inner">
+                <div class="msg-avatar" style="background:rgba(45,212,191,0.12);color:#2dd4bf;">👤</div>
+                <div class="msg-body" style="background:var(--bg-surface);border:1px solid var(--border);border-radius:16px 16px 16px 4px;padding:8px 12px;">
+                    <span style="color:#2dd4bf;font-size:12px;font-weight:600;">${esc(name)}</span>
+                    <div class="typing-dots"><span></span><span></span><span></span></div>
+                </div>
+            </div>`;
+        const container = document.getElementById('chatMessages');
+        if (container) container.scrollTop = container.scrollHeight;
+
+        // Auto-remove after 4s if no new event
+        clearTimeout(typing._timeout);
+        typing._timeout = setTimeout(() => typing.remove(), 4000);
+    });
+
+    // v0.23.2: User @mention notification
+    Events.on('user.mentioned', (payload) => {
+        if (!payload) return;
+        const channelId = payload.channel_id;
+        // Increment unread badge on the channel sidebar item
+        const ch = (App.channels || []).find(c => c.id === channelId);
+        if (ch) {
+            ch.unread = (ch.unread || 0) + 1;
+            if (typeof UI !== 'undefined') UI.renderChannelsSection();
+        }
+        // Toast with deep-link
+        const preview = payload.content || 'You were mentioned';
+        UI.toast(`@mention: ${preview}`, 'info');
+    });
+
+    // v0.23.2: Live presence updates for sidebar online dots
+    Events.on('user.presence', (payload) => {
+        if (!payload || !payload.user_id) return;
+        App.presence[payload.user_id] = payload.status || 'offline';
+        if (typeof UI !== 'undefined') UI.renderChannelsSection();
    });

    // Close modals on overlay click
--- a/src/js/debug.js
+++ b/src/js/debug.js
@@ -238,7 +238,7 @@ const DebugLog = {
        if (typeof App !== 'undefined') {
            snap.app = {
                chatCount: App.chats?.length || 0,
-                currentChatId: App.currentChatId,
+                activeConversation: App.activeConversation,
                modelCount: App.models?.length || 0,
                isGenerating: App.isGenerating,
                settings: {
--- a/src/js/files.js
+++ b/src/js/files.js
@@ -81,7 +81,7 @@ async function stageFile(file) {
    _updateSendBlock();

    // Ensure a channel exists (files are channel-scoped)
-    if (!App.currentChatId) {
+    if (!App.activeId) {
        try {
            const title = file.name.slice(0, 50);
            const selectedId = UI.getModelValue();
@@ -93,7 +93,7 @@ async function stageFile(file) {
                model, messages: [], messageCount: 0, updatedAt: resp.updated_at,
            };
            App.chats.unshift(chat);
-            App.currentChatId = chat.id;
+            App.setActive(chat.id, 'direct');
            UI.renderChatList();
        } catch (e) {
            staged.status = 'error';
@@ -106,7 +106,7 @@ async function stageFile(file) {

    // Upload
    try {
-        const result = await API.uploadFile(App.currentChatId, file);
+        const result = await API.uploadFile(App.activeId, file);
        staged.serverId = result.id;
        staged.status = _mapExtractionStatus(result.metadata?.extraction_status);
        staged.extractionStatus = result.metadata?.extraction_status || null;
--- a/src/js/knowledge-ui.js
+++ b/src/js/knowledge-ui.js
@@ -28,7 +28,7 @@ const KnowledgeUI = (() => {
        const popup = document.getElementById('kbPopup');
        if (!popup) return;

-        if (!App.currentChatId) {
+        if (!App.activeId) {
            popup.innerHTML = '<div class="kb-popup-empty">Start a conversation first</div>';
            popup.classList.add('open');
            return;
@@ -40,7 +40,7 @@ const KnowledgeUI = (() => {
        try {
            const [allResp, chResp] = await Promise.all([
                API.listKnowledgeBases(),
-                API.getChannelKBs(App.currentChatId),
+                API.getChannelKBs(App.activeId),
            ]);
            _allKBs = allResp.data || [];
            _channelKBs = chResp.data || [];
@@ -82,7 +82,7 @@ const KnowledgeUI = (() => {
    }

    async function _toggleChannelKB(kbId) {
-        if (!App.currentChatId) return;
+        if (!App.activeId) return;

        const linkedSet = new Set(_channelKBs.map(kb => kb.kb_id));
        if (linkedSet.has(kbId)) {
@@ -92,7 +92,7 @@ const KnowledgeUI = (() => {
        }

        try {
-            const resp = await API.setChannelKBs(App.currentChatId, [...linkedSet]);
+            const resp = await API.setChannelKBs(App.activeId, [...linkedSet]);
            _channelKBs = resp.data || [];
            const popup = document.getElementById('kbPopup');
            if (popup) _renderChannelPopup(popup);
@@ -506,9 +506,9 @@ const KnowledgeUI = (() => {
    /** Refresh channel KB state when switching chats. */
    async function onChatChanged() {
        _channelKBs = [];
-        if (App.currentChatId) {
+        if (App.activeId) {
            try {
-                const resp = await API.getChannelKBs(App.currentChatId);
+                const resp = await API.getChannelKBs(App.activeId);
                _channelKBs = resp.data || [];
            } catch { /* silent */ }
        }
--- a/src/js/notes.js
+++ b/src/js/notes.js
@@ -596,7 +596,7 @@ async function _navigateDaily(offset) {
 // ── Save-to-Note (from chat messages) ──

 async function saveMessageToNote(msgIndex) {
-    const chat = App.chats?.find(c => c.id === App.currentChatId);
+    const chat = App.chats?.find(c => c.id === App.activeId);
    const msg = chat?.messages?.[msgIndex];
    if (!msg) return;

@@ -617,7 +617,7 @@ async function saveMessageToNote(msgIndex) {
    // Show save-to-note modal
    _showSaveToNoteModal({
        content,
-        sourceChannelId: App.currentChatId || '',
+        sourceChannelId: App.activeId || '',
        sourceMessageId: msg.id || '',
        defaultTitle,
    });
--- a/src/js/projects-ui.js
+++ b/src/js/projects-ui.js
@@ -299,6 +299,23 @@ function showChatContextMenu(e, chatId) {
        <span class="ctx-icon">📁</span> Set workspace…
    </button>`;

+    // v0.23.2: Folder options
+    const folders = App.folders || [];
+    if (folders.length > 0 || chat.folderId) {
+        items += '<div class="ctx-divider"></div>';
+        if (chat.folderId) {
+            items += `<button class="ctx-item" onclick="moveChatToFolder('${chatId}',null);dismissChatContextMenu()">
+                <span class="ctx-icon">↩</span> Remove from folder
+            </button>`;
+        }
+        folders.forEach(f => {
+            if (f.id === chat.folderId) return; // skip current
+            items += `<button class="ctx-item" onclick="moveChatToFolder('${chatId}','${f.id}');dismissChatContextMenu()">
+                <span class="ctx-icon">📂</span> ${esc(f.name)}
+            </button>`;
+        });
+    }
+
    menu.innerHTML = items;

    // Position near cursor
@@ -341,7 +358,8 @@ function onChatDragStart(e, chatId) {

 function onChatDragEnd(e) {
    e.target.classList.remove('dragging');
-    document.querySelectorAll('.project-group.drag-over').forEach(el => el.classList.remove('drag-over'));
+    // Clear all drag-over highlights (projects, folders, section bodies, unfiled zone)
+    document.querySelectorAll('.drag-over').forEach(el => el.classList.remove('drag-over'));
 }

 function onProjectDragOver(e) {
@@ -370,6 +388,64 @@ async function onRecentDrop(e) {
    await moveChatToProject(chatId, null);
 }

+// v0.23.2: Folder drag-and-drop
+
+async function onFolderDrop(e, folderId) {
+    e.preventDefault();
+    e.stopPropagation();
+    e.currentTarget.classList.remove('drag-over');
+    const chatId = e.dataTransfer.getData('text/plain');
+    if (!chatId) return;
+    await moveChatToFolder(chatId, folderId);
+}
+
+async function onChatSectionDrop(e) {
+    e.preventDefault();
+    e.currentTarget.classList.remove('drag-over');
+    const chatId = e.dataTransfer.getData('text/plain');
+    if (!chatId) return;
+    const chat = App.chats.find(c => c.id === chatId);
+    if (!chat) return;
+
+    // Unfile from folder if filed
+    if (chat.folderId) {
+        await moveChatToFolder(chatId, null);
+    }
+    // Remove from project if in one
+    if (chat.projectId) {
+        await moveChatToProject(chatId, null);
+    }
+}
+
+async function moveChatToFolder(chatId, folderId) {
+    try {
+        await API.updateChannel(chatId, { folder: folderId || '' });
+        const chat = App.chats.find(c => c.id === chatId);
+        if (chat) chat.folderId = folderId || null;
+        UI.renderChatList();
+    } catch (e) {
+        UI.toast('Failed to move chat: ' + e.message, 'error');
+    }
+}
+
+async function onUnfiledDrop(e) {
+    e.preventDefault();
+    e.stopPropagation();
+    e.currentTarget.classList.remove('drag-over');
+    const chatId = e.dataTransfer.getData('text/plain');
+    if (!chatId) return;
+    const chat = App.chats.find(c => c.id === chatId);
+    if (!chat) return;
+    // Unfile from folder
+    if (chat.folderId) {
+        await moveChatToFolder(chatId, null);
+    }
+    // Remove from project
+    if (chat.projectId) {
+        await moveChatToProject(chatId, null);
+    }
+}
+
 // ── Project Header Menu ─────────────────────

 function showProjectMenu(e, projectId) {
@@ -1106,7 +1182,19 @@ async function loadFolders() {
 async function loadChannels() {
    try {
        const resp = await API.listSidebarChannels();
-        App.channels = (resp.channels || []).map(normalizeChannel);
+        App.channels = (resp.data || []).map(normalizeChannel);
+
+        // Query presence for DM partners
+        const dmPartnerIds = App.channels
+            .filter(c => c.type === 'dm' && c.dmPartnerId)
+            .map(c => c.dmPartnerId);
+        if (dmPartnerIds.length > 0) {
+            try {
+                const presResp = await API._get(`/api/v1/presence?users=${dmPartnerIds.join(',')}`);
+                App.presence = presResp.presence || {};
+            } catch (_) { /* non-critical */ }
+        }
+
        if (typeof UI !== 'undefined') UI.renderChannelsSection();
    } catch (e) {
        console.warn('[channels] load failed:', e.message);
@@ -1127,27 +1215,117 @@ function normalizeChannel(ch) {
    };
 }

+// v0.23.2: Load user list for @mention autocomplete and DM creation
+async function loadUsers() {
+    try {
+        const resp = await API._get('/api/v1/users/search?q=');
+        App.users = (resp.users || []).map(u => ({
+            id: u.id,
+            username: u.username,
+            displayName: u.display_name || u.username,
+        }));
+    } catch (e) {
+        console.warn('[users] load failed:', e.message);
+        App.users = [];
+    }
+}
+
 async function selectChannel(channelId) {
-    App.currentChannelId = channelId;
-    App.currentChatId    = null;   // clear chat selection
+    const ch = (App.channels || []).find(c => c.id === channelId);
+    App.setActive(channelId, ch?.type || 'channel');
    if (typeof UI !== 'undefined') {
        UI.renderChannelsSection();
        UI.renderChatList();
    }
+    // Ensure conversation object exists in App.chats for message caching
+    if (!App.chats.find(c => c.id === channelId)) {
+        App.chats.unshift({
+            id: channelId, title: ch?.name || 'Channel', type: ch?.type || 'channel',
+            model: '', messages: [], messageCount: 0, projectId: null,
+            workspace_id: null, updatedAt: ch?.updatedAt || new Date().toISOString(),
+            settings: {},
+        });
+    }
    // Load messages for this channel
    try {
+        const chat = App.chats.find(c => c.id === channelId);
        const resp = await API._get(`/api/v1/channels/${channelId}/messages`);
-        const messages = resp.messages || [];
-        if (typeof UI !== 'undefined') UI.renderMessages(messages);
+        const messages = (resp.data || []).map(m => ({
+            id: m.id,
+            parent_id: m.parent_id || null,
+            role: m.role,
+            content: m.content,
+            model: m.model || '',
+            modelName: '',
+            timestamp: m.created_at,
+            tool_calls: m.tool_calls || null,
+            metadata: m.metadata || null,
+            siblingCount: m.sibling_count || 1,
+            siblingIndex: m.sibling_index || 0,
+            participant_type: m.participant_type || null,
+            participant_id: m.participant_id || null,
+            sender_name: m.sender_name || null,
+            sender_avatar: m.sender_avatar || null,
+        }));
+        if (chat) chat.messages = messages;
+        if (typeof UI !== 'undefined') {
+            UI.renderMessages(messages);
+            UI.updateContextBanner();
+        }
    } catch (e) {
        console.warn('[channel] message load failed:', e.message);
    }
    try {
-        sessionStorage.setItem('cs-active-channel', channelId);
+        sessionStorage.setItem('cs-active-conversation', JSON.stringify(App.activeConversation));
    } catch (_) {}
+
+    // v0.23.2: Mark as read and clear unread badge
+    const selCh = (App.channels || []).find(c => c.id === channelId);
+    if (selCh) selCh.unread = 0;
+    API.markRead(channelId).catch(() => {});
 }

 async function newChannelOrDM() {
+    // Show choice: Channel or DM
+    const choice = await new Promise(resolve => {
+        const overlay = document.createElement('div');
+        overlay.className = 'modal-overlay active';
+        overlay.innerHTML = `
+            <div class="modal" style="width:340px;">
+                <div class="modal-header"><h3>New Conversation</h3></div>
+                <div class="modal-body" style="display:flex;flex-direction:column;gap:8px;padding:16px;">
+                    <button class="btn btn-primary" id="_ncChannel">
+                        <span style="margin-right:6px;">#</span> New Channel
+                    </button>
+                    <button class="btn" id="_ncDM">
+                        <span style="margin-right:6px;">@</span> New Direct Message
+                    </button>
+                    <button class="btn" id="_ncGroup">
+                        <span style="margin-right:6px;">👥</span> New Group Chat
+                    </button>
+                </div>
+            </div>`;
+        overlay.addEventListener('click', e => { if (e.target === overlay) { overlay.remove(); resolve(null); } });
+        overlay.querySelector('#_ncChannel').onclick = () => { overlay.remove(); resolve('channel'); };
+        overlay.querySelector('#_ncDM').onclick = () => { overlay.remove(); resolve('dm'); };
+        overlay.querySelector('#_ncGroup').onclick = () => { overlay.remove(); resolve('group'); };
+        document.body.appendChild(overlay);
+    });
+
+    if (choice === 'channel') {
+        await _createNewChannel();
+    } else if (choice === 'dm') {
+        await _createNewDM();
+    } else if (choice === 'group') {
+        if (typeof newGroupChat === 'function') {
+            await newGroupChat();
+        } else {
+            UI.toast('Group chat not available', 'warning');
+        }
+    }
+}
+
+async function _createNewChannel() {
    const result = await _showCreationDialog({
        title: 'New Channel',
        placeholder: 'Channel name',
@@ -1159,11 +1337,139 @@ async function newChannelOrDM() {
        const ch  = normalizeChannel(raw);
        App.channels = App.channels || [];
        App.channels.push(ch);
-        if (typeof UI !== 'undefined') UI.renderChannelsSection();
+        // Also add to App.chats for message caching / send path
+        App.chats.unshift({
+            id: raw.id, title: raw.title || result.name, type: 'channel',
+            model: '', messages: [], messageCount: 0, projectId: raw.project_id || null,
+            workspace_id: raw.workspace_id || null, updatedAt: raw.updated_at,
+            settings: raw.settings || {},
+        });
+        App.setActive(raw.id, 'channel');
+        if (typeof UI !== 'undefined') {
+            UI.renderChannelsSection();
+            UI.renderChatList();
+            UI.updateContextBanner();
+        }
        UI.toast(`#${result.name} created`, 'success');
    } catch (e) {
        UI.toast('Failed to create channel', 'error');
-        console.error('[newChannelOrDM]', e);
+        console.error('[newChannel]', e);
+    }
+}
+
+async function _createNewDM() {
+    return new Promise(resolve => {
+        const overlay = document.createElement('div');
+        overlay.className = 'modal-overlay active';
+        overlay.innerHTML = `
+            <div class="modal" style="width:360px;">
+                <div class="modal-header"><h3>New Direct Message</h3></div>
+                <div class="modal-body" style="padding:16px;">
+                    <input type="text" id="_dmSearchInput" class="input"
+                           placeholder="Search users…" autocomplete="off"
+                           style="width:100%;margin-bottom:8px;">
+                    <div id="_dmResults" style="max-height:200px;overflow-y:auto;"></div>
+                </div>
+                <div class="modal-footer">
+                    <button class="btn" id="_dmCancel">Cancel</button>
+                </div>
+            </div>`;
+
+        const input = overlay.querySelector('#_dmSearchInput');
+        const results = overlay.querySelector('#_dmResults');
+        let debounce = null;
+        let selectedUser = null;
+
+        const close = () => { overlay.remove(); resolve(); };
+        overlay.addEventListener('click', e => { if (e.target === overlay) close(); });
+        overlay.querySelector('#_dmCancel').onclick = close;
+
+        async function search(q) {
+            try {
+                const resp = await API._get(`/api/v1/users/search?q=${encodeURIComponent(q)}`);
+                const users = resp.users || [];
+                if (users.length === 0) {
+                    results.innerHTML = '<div style="padding:8px;color:var(--text-3);font-size:12px;">No users found</div>';
+                    return;
+                }
+                results.innerHTML = users.map(u => `
+                    <div class="dm-user-item" data-id="${u.id}" data-name="${esc(u.display_name || u.username)}"
+                         style="padding:8px 10px;cursor:pointer;border-radius:4px;display:flex;align-items:center;gap:8px;">
+                        <svg width="14" height="14" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" style="flex-shrink:0;">
+                            <path d="M20 21v-2a4 4 0 00-4-4H8a4 4 0 00-4 4v2"/><circle cx="12" cy="7" r="4"/>
+                        </svg>
+                        <span style="flex:1;overflow:hidden;text-overflow:ellipsis;white-space:nowrap;">
+                            <b>${esc(u.display_name || u.username)}</b>
+                            ${u.display_name ? `<span style="color:var(--text-3);font-size:11px;margin-left:4px;">@${esc(u.username)}</span>` : ''}
+                        </span>
+                    </div>
+                `).join('');
+
+                results.querySelectorAll('.dm-user-item').forEach(el => {
+                    el.onmouseenter = () => el.style.background = 'var(--bg-hover)';
+                    el.onmouseleave = () => el.style.background = '';
+                    el.onclick = async () => {
+                        const userId = el.dataset.id;
+                        const userName = el.dataset.name;
+                        overlay.remove();
+                        await _finishDMCreation(userId, userName);
+                        resolve();
+                    };
+                });
+            } catch (e) {
+                results.innerHTML = `<div style="padding:8px;color:var(--text-3);font-size:12px;">Search failed: ${esc(e.message)}</div>`;
+            }
+        }
+
+        input.addEventListener('input', () => {
+            clearTimeout(debounce);
+            const q = input.value.trim();
+            if (q.length === 0) {
+                // Show all users when empty
+                debounce = setTimeout(() => search(''), 100);
+                return;
+            }
+            debounce = setTimeout(() => search(q), 200);
+        });
+
+        document.body.appendChild(overlay);
+        input.focus();
+        // Show all users immediately
+        search('');
+    });
+}
+
+async function _finishDMCreation(targetId, targetName) {
+    try {
+        const raw = await API._post('/api/v1/channels', {
+            title: targetName,
+            type: 'dm',
+            participants: [targetId],
+        });
+        const ch = normalizeChannel(raw);
+        // Avoid duplicate in sidebar list (dedup guard may return existing)
+        if (!(App.channels || []).find(c => c.id === ch.id)) {
+            App.channels = App.channels || [];
+            App.channels.push(ch);
+        }
+        if (!App.chats.find(c => c.id === raw.id)) {
+            App.chats.unshift({
+                id: raw.id, title: raw.title || targetName,
+                type: 'dm', model: '', messages: [], messageCount: 0,
+                projectId: null, workspace_id: null, updatedAt: raw.updated_at,
+                settings: raw.settings || {},
+            });
+        }
+        App.setActive(raw.id, 'dm');
+        if (typeof UI !== 'undefined') {
+            UI.renderChannelsSection();
+            UI.renderChatList();
+            UI.updateContextBanner();
+        }
+        UI.toast(`DM with ${targetName}`, 'success');
+    } catch (e) {
+        UI.toast('Failed to create DM: ' + e.message, 'error');
+        console.error('[newDM]', e);
    }
 }

@@ -1191,6 +1497,162 @@ async function newFolder() {
    }
 }

+// ── Channel CRUD (v0.23.2) ─────────────────────
+
+function showChannelContextMenu(e, channelId) {
+    e.preventDefault();
+    e.stopPropagation();
+    dismissChatContextMenu();
+
+    const ch = (App.channels || []).find(c => c.id === channelId);
+    if (!ch) return;
+
+    const menu = document.createElement('div');
+    menu.className = 'project-ctx-menu';
+
+    let items = '';
+    items += `<button class="ctx-item" onclick="openParticipantsPanel('${channelId}');dismissChatContextMenu()">
+        <span class="ctx-icon">👥</span> Members
+    </button>`;
+    items += `<button class="ctx-item" onclick="renameChannel('${channelId}');dismissChatContextMenu()">
+        <span class="ctx-icon">✏</span> Rename
+    </button>`;
+    if (ch.type === 'channel' || ch.type === 'group') {
+        items += `<button class="ctx-item" onclick="editChannelTopic('${channelId}');dismissChatContextMenu()">
+            <span class="ctx-icon">💬</span> Set topic
+        </button>`;
+        items += `<button class="ctx-item" onclick="cycleChannelAiMode('${channelId}');dismissChatContextMenu()">
+            <span class="ctx-icon">🤖</span> AI mode: ${esc(ch.aiMode || 'auto')}
+        </button>`;
+    }
+    items += '<div class="ctx-divider"></div>';
+    items += `<button class="ctx-item" onclick="archiveChannel('${channelId}');dismissChatContextMenu()">
+        <span class="ctx-icon">📦</span> Archive
+    </button>`;
+    // Delete gated by retention mode (default=flexible allows delete)
+    const retentionMode = App.policies?.channel_retention_mode || 'flexible';
+    if (retentionMode === 'flexible') {
+        items += `<button class="ctx-item ctx-danger" onclick="deleteChannel('${channelId}');dismissChatContextMenu()">
+            <span class="ctx-icon">🗑</span> Delete
+        </button>`;
+    }
+
+    menu.innerHTML = items;
+    menu.style.left = Math.min(e.clientX, window.innerWidth - 180) + 'px';
+    menu.style.top = Math.min(e.clientY, window.innerHeight - 150) + 'px';
+
+    document.body.appendChild(menu);
+    _ctxMenu = menu;
+    setTimeout(() => document.addEventListener('click', dismissChatContextMenu, { once: true }), 0);
+}
+
+async function renameChannel(channelId) {
+    const ch = (App.channels || []).find(c => c.id === channelId);
+    if (!ch) return;
+    const result = await _showCreationDialog({
+        title: 'Rename Channel',
+        placeholder: 'Channel name',
+        withColor: false,
+        defaultValue: ch.name,
+        confirmLabel: 'Rename',
+    });
+    if (!result) return;
+    try {
+        await API.updateChannel(channelId, { title: result.name.trim() });
+        ch.name = result.name.trim();
+        // Also update in App.chats if present
+        const chat = App.chats.find(c => c.id === channelId);
+        if (chat) chat.title = result.name.trim();
+        if (typeof UI !== 'undefined') UI.renderChannelsSection();
+        UI.toast('Channel renamed', 'success');
+    } catch (e) {
+        UI.toast('Failed to rename channel', 'error');
+    }
+}
+
+async function editChannelTopic(channelId) {
+    const ch = (App.channels || []).find(c => c.id === channelId);
+    if (!ch) return;
+    const result = await _showCreationDialog({
+        title: 'Set Topic',
+        placeholder: 'Channel topic (optional)',
+        withColor: false,
+        defaultValue: ch.topic || '',
+        confirmLabel: 'Save',
+    });
+    if (!result) return;
+    try {
+        // Topic is now a proper field on updateChannelRequest (v0.23.2)
+        await API._put(`/api/v1/channels/${channelId}`, { topic: result.name.trim() });
+        ch.topic = result.name.trim();
+        if (typeof UI !== 'undefined') UI.updateContextBanner();
+        UI.toast('Topic updated', 'success');
+    } catch (e) {
+        UI.toast('Failed to set topic', 'error');
+    }
+}
+
+async function deleteChannel(channelId) {
+    if (!await showConfirm('Delete this channel and all its messages?')) return;
+    try {
+        await API.deleteChannel(channelId);
+        App.channels = (App.channels || []).filter(c => c.id !== channelId);
+        App.chats = App.chats.filter(c => c.id !== channelId);
+        if (App.activeId === channelId) {
+            App.setActive(null);
+            UI.showEmptyState();
+        }
+        if (typeof UI !== 'undefined') {
+            UI.renderChannelsSection();
+            UI.renderChatList();
+            UI.updateContextBanner();
+        }
+        UI.toast('Channel deleted', 'success');
+    } catch (e) {
+        UI.toast('Failed to delete: ' + e.message, 'error');
+    }
+}
+
+async function archiveChannel(channelId) {
+    try {
+        await API.updateChannel(channelId, { is_archived: true });
+        // Remove from sidebar (archived channels are hidden)
+        App.channels = (App.channels || []).filter(c => c.id !== channelId);
+        App.chats = App.chats.filter(c => c.id !== channelId);
+        if (App.activeId === channelId) {
+            App.setActive(null);
+            UI.showEmptyState();
+        }
+        if (typeof UI !== 'undefined') {
+            UI.renderChannelsSection();
+            UI.renderChatList();
+            UI.updateContextBanner();
+        }
+        UI.toast('Channel archived', 'success');
+    } catch (e) {
+        UI.toast('Failed to archive: ' + e.message, 'error');
+    }
+}
+
+// v0.23.2: Cycle ai_mode on click: auto → mention_only → off → auto
+async function cycleChannelAiMode(channelId) {
+    const ch = (App.channels || []).find(c => c.id === channelId);
+    if (!ch) return;
+    const order = ['auto', 'mention_only', 'off'];
+    const idx = order.indexOf(ch.aiMode || 'auto');
+    const next = order[(idx + 1) % order.length];
+    try {
+        await API.updateChannel(channelId, { ai_mode: next });
+        ch.aiMode = next;
+        if (typeof UI !== 'undefined') UI.updateContextBanner();
+        UI.toast(`AI mode: ${next === 'mention_only' ? '@mention only' : next}`, 'success');
+    } catch (e) {
+        UI.toast('Failed to change AI mode: ' + e.message, 'error');
+    }
+}
+
+// ── Folder Menu + CRUD ─────────────────────────
+
 function showFolderMenu(e, folderId) {
    e.preventDefault();
    e.stopPropagation();
@@ -1238,13 +1700,69 @@ async function renameFolder(folderId) {
 async function deleteFolder(folderId) {
    const folder = (App.folders || []).find(f => f.id === folderId);
    if (!folder) return;
-    // Move any chats in this folder back to unfiled before deleting
-    (App.chats || []).forEach(c => { if (c.folderId === folderId) c.folderId = null; });
+
+    const chatsInFolder = (App.chats || []).filter(c => c.folderId === folderId);
+
+    // If folder has chats, ask whether to preserve or delete them
+    let preserveChats = true;
+    if (chatsInFolder.length > 0) {
+        const choice = await new Promise(resolve => {
+            const overlay = document.createElement('div');
+            overlay.className = 'modal-overlay active';
+            overlay.innerHTML = `
+                <div class="modal" style="width:380px;">
+                    <div class="modal-header"><h3>Delete folder "${esc(folder.name)}"</h3></div>
+                    <div class="modal-body" style="padding:16px;font-size:13px;color:var(--text-2);">
+                        This folder contains <b>${chatsInFolder.length} chat${chatsInFolder.length > 1 ? 's' : ''}</b>.
+                        What should happen to them?
+                    </div>
+                    <div class="modal-footer" style="display:flex;gap:8px;justify-content:flex-end;">
+                        <button class="btn" id="_dfCancel">Cancel</button>
+                        <button class="btn btn-danger" id="_dfDeleteAll">Delete chats too</button>
+                        <button class="btn btn-primary" id="_dfPreserve">Keep chats</button>
+                    </div>
+                </div>`;
+            overlay.addEventListener('click', e => { if (e.target === overlay) { overlay.remove(); resolve(null); } });
+            overlay.querySelector('#_dfCancel').onclick = () => { overlay.remove(); resolve(null); };
+            overlay.querySelector('#_dfDeleteAll').onclick = () => { overlay.remove(); resolve('delete'); };
+            overlay.querySelector('#_dfPreserve').onclick = () => { overlay.remove(); resolve('preserve'); };
+            document.body.appendChild(overlay);
+        });
+
+        if (!choice) return; // cancelled
+        preserveChats = choice === 'preserve';
+    } else {
+        // Empty folder — just confirm
+        if (!await showConfirm(`Delete folder "${folder.name}"?`)) return;
+    }
+
    try {
+        if (preserveChats) {
+            // Unfile chats before deleting the folder
+            for (const c of chatsInFolder) {
+                c.folderId = null;
+            }
+        } else {
+            // Delete the chats in the folder
+            for (const c of chatsInFolder) {
+                try {
+                    await API.deleteChannel(c.id);
+                    // Clean up active state if deleting the active chat
+                    if (App.activeId === c.id) {
+                        App.setActive(null);
+                    }
+                } catch (_) { /* best effort */ }
+            }
+            App.chats = App.chats.filter(c => c.folderId !== folderId);
+        }
+
        await API.deleteFolder(folderId);
        App.folders = App.folders.filter(f => f.id !== folderId);
-        if (typeof UI !== 'undefined') UI.renderChatList();
-        UI.toast('Folder deleted', 'success');
+        if (typeof UI !== 'undefined') {
+            UI.renderChatList();
+            if (!preserveChats && !App.activeId) UI.showEmptyState();
+        }
+        UI.toast(preserveChats ? 'Folder deleted, chats preserved' : 'Folder and chats deleted', 'success');
    } catch (e) {
        UI.toast('Failed to delete folder', 'error');
        console.error('[deleteFolder]', e);
@@ -1255,11 +1773,172 @@ async function deleteFolder(folderId) {

 (function startPresenceHeartbeat() {
    const INTERVAL = 30000; // 30s
+    let timer = null;
    async function beat() {
        if (!API.isAuthed) return;
        try {
            await API.presenceHeartbeat();
        } catch (_) { /* non-critical */ }
    }
-    setInterval(beat, INTERVAL);
+    function start() {
+        if (timer) return;
+        beat(); // immediate on resume
+        timer = setInterval(beat, INTERVAL);
+    }
+    function stop() {
+        if (timer) { clearInterval(timer); timer = null; }
+    }
+    start();
+    document.addEventListener('visibilitychange', () => {
+        if (document.hidden) stop(); else start();
+    });
 })();
+
+// ── Participants Panel (v0.23.2) ──────────────────────────────────────────
+
+async function openParticipantsPanel(channelId) {
+    const overlay = document.createElement('div');
+    overlay.className = 'modal-overlay active';
+    overlay.id = '_participantsOverlay';
+    overlay.innerHTML = `
+        <div class="modal" style="width:440px;max-height:80vh;display:flex;flex-direction:column;">
+            <div class="modal-header"><h3>Channel Participants</h3></div>
+            <div class="modal-body" id="_participantsList" style="padding:12px;overflow-y:auto;flex:1;">
+                <div class="loading">Loading…</div>
+            </div>
+            <div style="padding:12px;border-top:1px solid var(--border);display:flex;gap:8px;">
+                <button class="btn btn-primary" id="_addUserBtn" style="flex:1;">+ Add User</button>
+                <button class="btn" id="_addPersonaBtn" style="flex:1;">+ Add Persona</button>
+            </div>
+            <div style="padding:0 12px 12px;">
+                <button class="btn" style="width:100%;" id="_closeParticipants">Close</button>
+            </div>
+        </div>`;
+    overlay.addEventListener('click', e => { if (e.target === overlay) overlay.remove(); });
+    overlay.querySelector('#_closeParticipants').onclick = () => overlay.remove();
+    overlay.querySelector('#_addUserBtn').onclick = () => _showAddParticipantSearch(channelId, 'user');
+    overlay.querySelector('#_addPersonaBtn').onclick = () => _showAddParticipantSearch(channelId, 'persona');
+    document.body.appendChild(overlay);
+
+    await _refreshParticipantsList(channelId);
+}
+
+async function _refreshParticipantsList(channelId) {
+    const el = document.getElementById('_participantsList');
+    if (!el) return;
+    try {
+        const resp = await API._get(`/api/v1/channels/${channelId}/participants`);
+        const parts = resp.participants || [];
+        if (parts.length === 0) {
+            el.innerHTML = '<div class="empty-hint">No participants yet</div>';
+            return;
+        }
+        el.innerHTML = parts.map(p => {
+            const icon = p.participant_type === 'persona' ? '⚡' : '👤';
+            // Resolve name: display_name from record, or look up in App state
+            let name = p.display_name;
+            if (!name && p.participant_type === 'user') {
+                const u = (App.users || []).find(u => u.id === p.participant_id);
+                name = u?.displayName || u?.username || null;
+                // Also check current user
+                if (!name && API.user && API.user.id === p.participant_id) {
+                    name = API.user.display_name || API.user.username;
+                }
+            }
+            if (!name && p.participant_type === 'persona') {
+                const m = (App.models || []).find(m => m.personaId === p.participant_id);
+                name = m?.name || null;
+            }
+            if (!name) name = p.participant_id.slice(0, 8) + '…';
+            const role = p.role || 'member';
+            return `<div style="display:flex;align-items:center;gap:8px;padding:6px 0;border-bottom:1px solid var(--border-faint);">
+                <span style="font-size:16px;">${icon}</span>
+                <span style="flex:1;font-size:13px;">${esc(name)}</span>
+                <span style="font-size:11px;color:var(--text-3);">${esc(p.participant_type)} · ${esc(role)}</span>
+                ${role !== 'owner' ? `<button class="btn-small" style="color:var(--danger);"
+                    onclick="_removeParticipant('${channelId}','${p.id}')">✕</button>` : ''}
+            </div>`;
+        }).join('');
+    } catch (e) {
+        el.innerHTML = `<div class="empty-hint">Failed to load: ${esc(e.message)}</div>`;
+    }
+}
+
+async function _showAddParticipantSearch(channelId, pType) {
+    const overlay = document.createElement('div');
+    overlay.className = 'modal-overlay active';
+    overlay.style.zIndex = '10001';
+    const label = pType === 'persona' ? 'Persona' : 'User';
+    overlay.innerHTML = `
+        <div class="modal" style="width:360px;">
+            <div class="modal-header"><h3>Add ${label}</h3></div>
+            <div class="modal-body" style="padding:12px;">
+                <input class="input-full" id="_addPartSearch" placeholder="Search ${label.toLowerCase()}s…" autocomplete="off">
+                <div id="_addPartResults" style="margin-top:8px;max-height:200px;overflow-y:auto;"></div>
+            </div>
+        </div>`;
+    overlay.addEventListener('click', e => { if (e.target === overlay) overlay.remove(); });
+    document.body.appendChild(overlay);
+
+    const input = overlay.querySelector('#_addPartSearch');
+    const results = overlay.querySelector('#_addPartResults');
+    input.focus();
+
+    let debounce = null;
+    input.addEventListener('input', () => {
+        clearTimeout(debounce);
+        debounce = setTimeout(async () => {
+            const q = input.value.trim();
+            if (q.length < 1) { results.innerHTML = ''; return; }
+            try {
+                let items = [];
+                if (pType === 'user') {
+                    const resp = await API._get(`/api/v1/users/search?q=${encodeURIComponent(q)}`);
+                    items = (resp.users || []).map(u => ({ id: u.id, name: u.display_name || u.username }));
+                } else {
+                    // Search personas from App.models
+                    items = (App.models || [])
+                        .filter(m => m.isPersona && (m.name || '').toLowerCase().includes(q.toLowerCase()))
+                        .map(m => ({ id: m.personaId, name: m.name }));
+                }
+                if (items.length === 0) {
+                    results.innerHTML = '<div class="empty-hint" style="font-size:12px;">No matches</div>';
+                    return;
+                }
+                results.innerHTML = items.slice(0, 10).map(item =>
+                    `<div style="padding:6px 8px;cursor:pointer;border-radius:4px;font-size:13px;"
+                          class="hover-bg"
+                          onclick="_addParticipant('${channelId}','${pType}','${item.id}');this.closest('.modal-overlay').remove();">
+                        ${pType === 'persona' ? '⚡' : '👤'} ${esc(item.name)}
+                    </div>`
+                ).join('');
+            } catch (_) {
+                results.innerHTML = '<div class="empty-hint" style="font-size:12px;">Search failed</div>';
+            }
+        }, 250);
+    });
+}
+
+async function _addParticipant(channelId, pType, participantId) {
+    try {
+        await API._post(`/api/v1/channels/${channelId}/participants`, {
+            participant_type: pType,
+            participant_id: participantId,
+            role: 'member',
+        });
+        UI.toast(`${pType === 'persona' ? 'Persona' : 'User'} added`, 'success');
+        await _refreshParticipantsList(channelId);
+    } catch (e) {
+        UI.toast('Failed to add: ' + e.message, 'error');
+    }
+}
+
+async function _removeParticipant(channelId, recordId) {
+    try {
+        await API._del(`/api/v1/channels/${channelId}/participants/${recordId}`);
+        UI.toast('Participant removed', 'success');
+        await _refreshParticipantsList(channelId);
+    } catch (e) {
+        UI.toast('Failed to remove: ' + e.message, 'error');
+    }
+}
--- a/src/js/tokens.js
+++ b/src/js/tokens.js
@@ -81,7 +81,7 @@ function updateInputTokens() {
    const budget = Tokens.getContextBudget();
    if (budget.maxContext > 0) {
        // Show relative to available context
-        const chat = App.chats.find(c => c.id === App.currentChatId);
+        const chat = App.chats.find(c => c.id === App.activeId);
        const convTokens = Tokens.estimateConversation(chat?.messages || [], App.settings.systemPrompt);
        // Include staged file estimates
        const fileTokens = Tokens.estimateFiles(
@@ -114,7 +114,7 @@ function updateContextWarning() {
        return;
    }

-    const chat = App.chats.find(c => c.id === App.currentChatId);
+    const chat = App.chats.find(c => c.id === App.activeId);
    if (!chat || !chat.messages?.length) {
        warning.style.display = 'none';
        return;
--- a/src/js/ui-admin.js
+++ b/src/js/ui-admin.js
@@ -47,6 +47,7 @@ const ADMIN_LOADERS = {
    usage:      () => UI.loadAdminUsage(),
    audit:      () => UI.loadAuditLog(),
    stats:      () => UI.loadAdminStats(),
+    channels:   () => UI.loadAdminChannels(),
 };

 // Find which category a section belongs to
@@ -1447,4 +1448,55 @@ Object.assign(UI, {
        prev.style.color = fg;
    },

+    // ── Admin Channels (v0.23.2) ──────────────
+
+    async loadAdminChannels() {
+        const list = document.getElementById('adminArchivedList');
+        const countEl = document.getElementById('adminArchivedCount');
+        const modeEl = document.getElementById('adminRetentionMode');
+        if (!list) return;
+
+        try {
+            const resp = await API._get('/api/v1/admin/channels/archived');
+            const channels = resp.channels || [];
+            if (countEl) countEl.textContent = channels.length;
+            if (modeEl) modeEl.textContent = resp.retention_mode || 'flexible';
+
+            if (channels.length === 0) {
+                list.innerHTML = '<div class="empty-hint">No archived channels</div>';
+                return;
+            }
+
+            let html = '<table class="admin-table"><thead><tr>' +
+                '<th>Title</th><th>Type</th><th>Owner</th><th>Messages</th><th>Archived</th><th></th>' +
+                '</tr></thead><tbody>';
+            for (const ch of channels) {
+                const age = _relativeTime(ch.updated_at);
+                html += `<tr>
+                    <td>${esc(ch.title || 'Untitled')}</td>
+                    <td>${esc(ch.type)}</td>
+                    <td>${esc(ch.owner_name)}</td>
+                    <td>${ch.message_count}</td>
+                    <td>${age}</td>
+                    <td><button class="btn-small btn-danger" onclick="UI._purgeChannel('${ch.id}')">Purge</button></td>
+                </tr>`;
+            }
+            html += '</tbody></table>';
+            list.innerHTML = html;
+        } catch (e) {
+            list.innerHTML = `<div class="empty-hint">Failed to load: ${esc(e.message)}</div>`;
+        }
+    },
+
+    async _purgeChannel(channelId) {
+        if (!await showConfirm('Permanently delete this archived channel and all its messages? This cannot be undone.')) return;
+        try {
+            await API._del(`/api/v1/admin/channels/${channelId}/purge`);
+            UI.toast('Channel purged', 'success');
+            UI.loadAdminChannels(); // refresh list
+        } catch (e) {
+            UI.toast('Purge failed: ' + e.message, 'error');
+        }
+    },
+
 });
--- a/src/js/ui-core.js
+++ b/src/js/ui-core.js
@@ -12,7 +12,7 @@ function avatarHTML(role, avatarDataURI) {
    if (avatarDataURI) {
        return `<img src="${avatarDataURI}" alt="" class="msg-avatar-img">`;
    }
-    return role === 'user' ? '👤' : '🤖';
+    return role === 'user' ? '👤' : role === 'other-user' ? '👤' : '🤖';
 }

 // Look up the current model/persona avatar for assistant messages.
@@ -394,7 +394,7 @@ const UI = {

        let html = '';
        channels.forEach(ch => {
-            const isActive  = App.currentChannelId === ch.id;
+            const isActive  = App.activeId === ch.id;
            const isDM      = ch.type === 'dm';
            const isChannel = ch.type === 'channel';
            const online    = App.presence?.[ch.dmPartnerId] === 'online';
@@ -413,9 +413,11 @@ const UI = {

            html += `<div class="sb-channel-item${isActive ? ' active' : ''}"
                          onclick="selectChannel('${ch.id}')"
+                          oncontextmenu="showChannelContextMenu(event,'${ch.id}')"
                          title="${esc(ch.name)}">
                <span class="sb-ch-icon">${icon}</span>
-                ${!collapsed ? `<span class="sb-ch-name">${esc(ch.name)}</span>${onlineDot}${unreadBadge}` : unreadBadge}
+                ${!collapsed ? `<span class="sb-ch-name">${esc(ch.name)}</span>${onlineDot}${unreadBadge}
+                <button class="sb-ch-menu" onclick="event.stopPropagation();showChannelContextMenu(event,'${ch.id}')" title="Options">⋯</button>` : unreadBadge}
            </div>`;
        });

@@ -470,18 +472,21 @@ const UI = {

        let html = '';

-        // Folder groups — always render, even when empty
+        // Folder groups — always render, even when empty (with drag handlers)
        folders.forEach(f => {
            const items = folderMap[f.id] || [];
            const isOpen = !App.collapsedFolders?.[f.id];
-            html += `<div class="sb-folder-group">
+            html += `<div class="sb-folder-group"
+                          ondragover="event.preventDefault();event.dataTransfer.dropEffect='move';this.classList.add('drag-over')"
+                          ondragleave="this.classList.remove('drag-over')"
+                          ondrop="onFolderDrop(event,'${f.id}')">
                <div class="sb-folder-header" onclick="UI.toggleFolder('${f.id}')">
                    <svg width="12" height="12" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2">
                        <path d="M22 19a2 2 0 01-2 2H4a2 2 0 01-2-2V5a2 2 0 012-2h5l2 3h9a2 2 0 012 2z"/>
                    </svg>
                    <span class="sb-folder-name">${esc(f.name)}</span>
-                    <span class="sb-folder-arrow">${isOpen ? '▾' : '▸'}</span>
                    <button class="sb-folder-menu" onclick="event.stopPropagation();showFolderMenu(event,'${f.id}')" title="Folder options">⋯</button>
+                    <span class="sb-folder-arrow">${isOpen ? '▾' : '▸'}</span>
                </div>
                ${isOpen
                    ? (items.length > 0
@@ -503,6 +508,17 @@ const UI = {
            else                   groups.older.push(c);
        });

+        // When folders exist, wrap unfiled chats in a drop zone
+        if (folders.length > 0) {
+            html += `<div class="sb-unfiled-zone"
+                          ondragover="event.preventDefault();event.dataTransfer.dropEffect='move';this.classList.add('drag-over')"
+                          ondragleave="this.classList.remove('drag-over')"
+                          ondrop="onUnfiledDrop(event)">`;
+            if (unfiled.length === 0) {
+                html += '<div class="sb-unfiled-hint">Drop here to unfile</div>';
+            }
+        }
+
        const renderTimeGroup = (label, items) => {
            if (!items.length) return;
            html += `<div class="chat-group-label">${label}</div>`;
@@ -514,6 +530,10 @@ const UI = {
        renderTimeGroup('Previous 7 days', groups.week);
        renderTimeGroup('Older', groups.older);

+        if (folders.length > 0) {
+            html += '</div>'; // close .sb-unfiled-zone
+        }
+
        el.innerHTML = html;

        // Always keep projects section in sync
@@ -528,7 +548,7 @@ const UI = {

    _chatItemHTML(c, indented = false) {
        const time   = _relativeTime(c.updatedAt);
-        const active = c.id === App.currentChatId ? ' active' : '';
+        const active = c.id === App.activeId ? ' active' : '';
        const indent = indented ? ' indented' : '';
        const typeIcon = c.type === 'group'
            ? '<span class="chat-type-icon" title="Group Chat">👥</span> '
@@ -617,19 +637,40 @@ const UI = {
        // Skip summary messages in normal rendering — they get _summaryHTML
        if (_isSummaryMessage(msg)) return '';
        const time = msg.timestamp ? new Date(msg.timestamp).toLocaleTimeString([], { hour: '2-digit', minute: '2-digit' }) : '';
-        let assistantLabel = 'Assistant';
-        if (!isUser) {
-            // Use stored modelName, or resolve from channel roster, or model list, or fall back
-            if (msg.modelName) {
-                assistantLabel = msg.modelName;
+
+        // v0.23.2: Sender attribution — distinguish self from other humans
+        const isSelf = !isUser ? false
+            : (!msg.participant_id || msg.participant_id === API.user?.id);
+        const isOtherUser = isUser && !isSelf;
+
+        let senderLabel = 'You';
+        let senderAvatarURI = API.user?.avatar || null;
+
+        if (isOtherUser) {
+            senderLabel = msg.sender_name || 'User';
+            senderAvatarURI = msg.sender_avatar || null;
+        } else if (!isUser) {
+            // Assistant message — use model/persona label
+            senderLabel = 'Assistant';
+            senderAvatarURI = assistantAvatarURI(msg);
+            if (msg.sender_name) {
+                senderLabel = msg.sender_name;
+            } else if (msg.modelName) {
+                senderLabel = msg.modelName;
            } else if (typeof ChannelModels !== 'undefined' && msg.model) {
-                assistantLabel = ChannelModels.resolveDisplayName(msg.model);
+                senderLabel = ChannelModels.resolveDisplayName(msg.model);
            } else if (msg.model) {
                const m = App.models.find(x => x.id === msg.model || x.baseModelId === msg.model);
-                assistantLabel = m?.name || msg.model;
+                senderLabel = m?.name || msg.model;
+            }
+            if (msg.sender_avatar) {
+                senderAvatarURI = msg.sender_avatar;
            }
        }

+        // CSS class: self = right-aligned "user", other humans = left-aligned "other-user", AI = "assistant"
+        const roleClass = isSelf ? 'user' : isOtherUser ? 'other-user' : msg.role;
+
        // Branch indicator: show ‹ 2/3 › when siblings exist
        const hasSiblings = (msg.siblingCount || 1) > 1;
        const sibPos = (msg.siblingIndex || 0) + 1; // display as 1-indexed
@@ -645,16 +686,16 @@ const UI = {

        // Action buttons
        const msgId = msg.id ? esc(msg.id) : '';
-        const editBtn = isUser && msgId ? `<button class="msg-action-btn" onclick="editMessage('${msgId}')" title="Edit">Edit</button>` : '';
+        const editBtn = isSelf && msgId ? `<button class="msg-action-btn" onclick="editMessage('${msgId}')" title="Edit">Edit</button>` : '';
        const regenBtn = !isUser && msgId ? `<button class="msg-action-btn" onclick="regenerateMessage('${msgId}')" title="Regenerate">Regen</button>` : '';

        return `
-            <div class="message ${msg.role}${dimmed ? ' msg-dimmed' : ''}" data-msg-id="${msgId}">
+            <div class="message ${roleClass}${dimmed ? ' msg-dimmed' : ''}" data-msg-id="${msgId}">
                <div class="msg-inner">
-                    <div class="msg-avatar">${avatarHTML(msg.role, isUser ? API.user?.avatar : assistantAvatarURI(msg))}</div>
+                    <div class="msg-avatar">${avatarHTML(isOtherUser ? 'other-user' : msg.role, senderAvatarURI)}</div>
                    <div class="msg-body">
                        <div class="msg-head">
-                            <span class="msg-role">${isUser ? 'You' : esc(assistantLabel)}</span>
+                            <span class="msg-role">${esc(senderLabel)}</span>
                            ${branchNav}
                            ${time ? `<span class="msg-time">${time}</span>` : ''}
                            <div class="msg-actions">
@@ -680,6 +721,45 @@ const UI = {
                <h2>Chat Switchboard</h2>
                <p>Select a model and start chatting</p>
            </div>`;
+        this.updateContextBanner();
+    },
+
+    // v0.23.2: Show/hide context banner based on active conversation type
+    updateContextBanner() {
+        const el = document.getElementById('channelContextBanner');
+        if (!el) return;
+        const ac = App.activeConversation;
+        if (!ac || ac.type === 'direct') {
+            el.style.display = 'none';
+            return;
+        }
+
+        let html = '';
+        if (ac.type === 'dm') {
+            const ch = (App.channels || []).find(c => c.id === ac.id);
+            const name = ch?.name || 'someone';
+            html = `<span class="ctx-mode">DM</span>` +
+                   `<span>with <b>${esc(name)}</b></span>` +
+                   `<span class="ctx-hint">@mention a persona to bring in AI</span>` +
+                   `<span style="flex:1;"></span>` +
+                   `<button class="ctx-participants-btn" onclick="openParticipantsPanel('${ac.id}')" title="Manage participants">👥 Members</button>`;
+        } else if (ac.type === 'group') {
+            html = `<span class="ctx-mode">Group</span>` +
+                   `<span class="ctx-hint">No @mention = leader responds · @mention to route · @all for everyone</span>` +
+                   `<span style="flex:1;"></span>` +
+                   `<button class="ctx-participants-btn" onclick="openParticipantsPanel('${ac.id}')" title="Manage participants">👥 Members</button>`;
+        } else if (ac.type === 'channel') {
+            const ch = (App.channels || []).find(c => c.id === ac.id);
+            const mode = ch?.aiMode || 'auto';
+            const topic = ch?.topic || '';
+            const modeLabel = mode === 'auto' ? 'AI: auto' : mode === 'mention_only' ? 'AI: @mention only' : 'AI: off';
+            html = `<button class="ctx-mode ctx-mode-btn" onclick="cycleChannelAiMode('${ac.id}')" title="Click to change AI mode">${esc(modeLabel)}</button>`;
+            if (topic) html += `<span class="ctx-topic">${esc(topic)}</span>`;
+            html += `<span style="flex:1;"></span>`;
+            html += `<button class="ctx-participants-btn" onclick="openParticipantsPanel('${ac.id}')" title="Manage participants">👥 Members</button>`;
+        }
+        el.innerHTML = html;
+        el.style.display = '';
    },

    showEditInline(messageId, currentContent) {
@@ -1278,7 +1358,7 @@ const UI = {
    // ── Export ────────────────────────────────

    exportChat(format) {
-        const chat = App.chats.find(c => c.id === App.currentChatId);
+        const chat = App.getActiveChat();
        if (!chat) return UI.toast('No chat to export', 'warning');

        let content, ext, mime;
@@ -1302,7 +1382,7 @@ const UI = {
    // ── Message Actions ──────────────────────

    copyMessage(index) {
-        const chat = App.chats.find(c => c.id === App.currentChatId);
+        const chat = App.getActiveChat();
        if (chat?.messages[index]) {
            navigator.clipboard.writeText(chat.messages[index].content)
                .then(() => UI.toast('Copied', 'success'))
--- a/src/js/ui-format.js
+++ b/src/js/ui-format.js
@@ -58,35 +58,44 @@ function formatMessage(content) {
 function _highlightMentions(html) {
    if (typeof ChannelModels === 'undefined') return html;
    const roster = ChannelModels.getRoster();
-    if (!roster || roster.length < 2) return html;

-    // Build patterns from handles (primary) and display names (fallback)
-    const patterns = [];
+    // Build patterns from roster handles and display names (AI mentions)
+    const aiPatterns = [];
    const seen = new Set();

+    if (roster && roster.length >= 2) {
        for (const m of roster) {
-        // Handle pattern (preferred)
            if (m.handle) {
                const escaped = m.handle.replace(/[.*+?^${}()|[\]\\]/g, '\\$&');
                if (!seen.has(escaped)) {
-                patterns.push(new RegExp('(@' + escaped + ')(?=[\\s.,!?;:)\\]}<]|$)', 'gi'));
+                    aiPatterns.push(new RegExp('(@' + escaped + ')(?=[\\s.,!?;:)\\]}<]|$)', 'gi'));
                    seen.add(escaped);
                }
            }
-        // Display name pattern (hyphenated form)
            if (m.display_name) {
                const hyphenated = m.display_name.replace(/\s+/g, '-');
                const escaped = hyphenated.replace(/[.*+?^${}()|[\]\\]/g, '\\$&');
                if (!seen.has(escaped.toLowerCase())) {
                    const flexible = escaped.replace(/[-]+/g, '[\\s-]+');
-                patterns.push(new RegExp('(@' + flexible + ')(?=[\\s.,!?;:)\\]}<]|$)', 'gi'));
+                    aiPatterns.push(new RegExp('(@' + flexible + ')(?=[\\s.,!?;:)\\]}<]|$)', 'gi'));
                    seen.add(escaped.toLowerCase());
                }
            }
        }
+    }

-    // @all
-    patterns.push(new RegExp('(@all)(?=[\\s.,!?;:)\\]}<]|$)', 'gi'));
+    // @all is special
+    aiPatterns.push(new RegExp('(@all)(?=[\\s.,!?;:)\\]}<]|$)', 'gi'));
+
+    // v0.23.2: Build user mention patterns
+    const userPatterns = [];
+    for (const u of (App.users || [])) {
+        const escaped = u.username.replace(/[.*+?^${}()|[\]\\]/g, '\\$&');
+        if (!seen.has(escaped.toLowerCase())) {
+            userPatterns.push(new RegExp('(@' + escaped + ')(?=[\\s.,!?;:)\\]}<]|$)', 'gi'));
+            seen.add(escaped.toLowerCase());
+        }
+    }

    // Don't highlight inside <code>, <pre>, <a> tags
    const parts = html.split(/(<[^>]+>)/);
@@ -101,9 +110,14 @@ function _highlightMentions(html) {
        }
        if (inCode) continue;
        let text = part;
-        for (const re of patterns) {
+        // AI mentions first (persona/model)
+        for (const re of aiPatterns) {
            text = text.replace(re, '<span class="mention-pill">$1</span>');
        }
+        // User mentions (different color)
+        for (const re of userPatterns) {
+            text = text.replace(re, '<span class="mention-pill mention-user">$1</span>');
+        }
        parts[i] = text;
    }
    return parts.join('');
--- a/src/js/ui-settings.js
+++ b/src/js/ui-settings.js
@@ -106,6 +106,11 @@ Object.assign(UI, {
        const prefs = JSON.parse(localStorage.getItem('cs-appearance') || '{}');
        if (scaleEl) prefs.scale = parseInt(scaleEl.value);
        if (msgFontEl) prefs.msgFont = parseInt(msgFontEl.value);
+        // v0.23.2: Theme saved via Theme API (localStorage key: switchboard_theme)
+        const activeThemeBtn = document.querySelector('#themeToggle .theme-btn.active');
+        if (activeThemeBtn && typeof Theme !== 'undefined') {
+            Theme.set(activeThemeBtn.dataset.theme);
+        }
        localStorage.setItem('cs-appearance', JSON.stringify(prefs));
        UI.toast('Appearance saved', 'success');
    },
@@ -141,7 +146,8 @@ Object.assign(UI, {
        const prefs = JSON.parse(localStorage.getItem('cs-appearance') || '{}');
        const scale = prefs.scale || 100;
        const msgFont = prefs.msgFont || 14;
-        const theme = prefs.theme || 'system';
+        // v0.23.2: Read theme from Theme API
+        const theme = typeof Theme !== 'undefined' ? Theme.get() : 'system';
        const keymap = prefs.editorKeymap || 'standard';

        const scaleEl = document.getElementById('settingsScale');
@@ -149,9 +155,14 @@ Object.assign(UI, {
        if (scaleEl) { scaleEl.value = scale; document.getElementById('scaleValue').textContent = scale + '%'; }
        if (msgFontEl) { msgFontEl.value = msgFont; document.getElementById('msgFontValue').textContent = msgFont + 'px'; }

-        // Highlight active theme button
+        // Highlight active theme button and wire click
        document.querySelectorAll('#themeToggle .theme-btn').forEach(btn => {
            btn.classList.toggle('active', btn.dataset.theme === theme);
+            btn.onclick = () => {
+                document.querySelectorAll('#themeToggle .theme-btn').forEach(b => b.classList.remove('active'));
+                btn.classList.add('active');
+                if (typeof Theme !== 'undefined') Theme.set(btn.dataset.theme);
+            };
        });

        // Highlight active keymap button
@@ -1 +1 @@
 .23.1
 .23.2