Changeset 0.18.1 (#80)

CHANGELOG.md

@@ -2,6 +2,71 @@
 
 All notable changes to Chat Switchboard.
 
+## [0.18.1] — 2026-02-28
+
+### Added
+- **Side panel architecture.** Complete rewrite of the side panel system
+  from shared-tab layout to independent single-slot panels. Any action
+  (preview, notes, diagram pop-out) fills the slot, replacing whatever
+  was there — no tabs, no association between panel types.
+- **Panel registry** (`PanelRegistry`): named panels with independent
+  open/close state, scroll/state preservation across switches, keyboard
+  shortcuts (Ctrl+\ cycle, Ctrl+Shift+\ toggle dual-view).
+- **Dual-view mode**: two panels side-by-side via CSS grid with a
+  drag-adjustable split ratio (0.2–0.8 range, 6px divider handle).
+  Toggle button in header actions area alongside fullscreen and close.
+- **Live HTML preview**: streaming responses update the preview iframe
+  in real-time (500ms debounce). Extracts the last fenced HTML block
+  from partial content and renders it as the response streams in.
+- **Extension pop-out**: `⧉` button on rendered extension blocks
+  (mermaid, KaTeX, etc.) clones the content into the preview iframe
+  and opens the side panel.
+- **Extension UI primitives** (`ctx.ui`): seven methods exposed to
+  browser extensions through the scoped extension context:
+  - `toast(msg, type)` — toast notifications via `UI.toast()`
+  - `openPreview(html)` — load HTML into side panel preview iframe
+  - `isDark()` — theme detection without DOM sniffing
+  - `isMobile()` — viewport width check (≤768px)
+  - `isPanelOpen()` — side panel container visibility
+  - `confirm(msg, opts)` — modal confirm dialog (Promise\<boolean>)
+  - `createMenu(anchor, opts)` — popup menu (unchanged from stub)
+- **Mermaid context-aware expand**: single `⛶` button replaces the
+  previous two-button (pop-out + fullscreen) approach. When the side
+  panel is open, expand pops the diagram into it; when closed, expand
+  goes fullscreen.
+- **Mermaid fullscreen close button**: 40px circular close button
+  overlaid top-right in fullscreen mode, 48px on mobile. Fixes the
+  previous Escape-key-only exit which was unusable on touch devices.
+- **Mobile side panel**: swipe navigation between panels (80px
+  threshold, 1.5× horizontal-to-vertical ratio), tap-to-close overlay,
+  responsive auto-collapse of dual mode on narrow viewports, enlarged
+  touch targets for all panel controls.
+- **Side panel header label**: simple text label showing the active
+  panel name, replacing the previous tab bar UI.
+
+### Changed
+- Side panel model changed from tabbed (Preview + Notes tabs visible
+  simultaneously) to single-slot (one panel fills the space, actions
+  replace it). No user-selectable tabs — content is entirely
+  action-driven.
+- Dual-view toggle button moved from tab bar (dynamically injected)
+  to static header actions area next to fullscreen and close.
+- Mermaid extension refactored to use `ctx.ui` primitives exclusively.
+  Zero direct references to `UI.*`, `PanelRegistry.*`, or DOM class
+  sniffing for theme detection. Extension remains fully self-contained
+  in `extensions/builtin/mermaid-renderer/`.
+- Mermaid source copy uses `ctx.ui.toast()` instead of inline button
+  text swap. Theme detection uses `ctx.ui.isDark()` instead of manual
+  `document.body.classList.contains('dark-theme')` check.
+- Side panel outer resize minimum bumped to 480px in dual mode (vs
+  280px single).
+
+### Removed
+- Tab bar UI (`.side-panel-tabs`, `.side-panel-tab`, tab rendering
+  logic). Panels no longer have user-selectable tabs.
+- Separate pop-out and fullscreen buttons in mermaid toolbar (collapsed
+  into single context-aware expand button).
+
 ## [0.18.0] — 2026-02-28
 
 ### Added
@@ -1080,4 +1145,4 @@ All notable changes to Chat Switchboard.
 
 ### Changed
 - Backward-compatible API routes with v0.8 field name aliases
-- User model preferences table (`user_model_settings`)
+- User model preferences table (`user_model_settings`)