rebrand + purge orphaned frontend: Chat Switchboard → Switchboard Core

Branding: bulk rename across 50+ files (Go, JS, CSS, HTML, YAML, JSON,
shell scripts). Fix Helm chart description and git repo URLs.
Fix test helper taglines.

Admin surface: strip 14 gutted tabs (providers, models, personas,
roles, knowledge, memory, tasks, health, routing, capabilities,
channels, dashboard, usage, stats). Collapse to 4 categories:
People, Workflows, System, Monitoring.

Settings surface: strip 11 gutted tabs (models, personas, providers,
roles, knowledge, memory, usage, workflows, tasks, data, gitkeys).
Keep: general, appearance, profile, teams, connections, notifications.

Team-admin surface: strip 5 gutted tabs (personas, providers,
knowledge, tasks, usage). Keep: members, groups, connections,
workflows, settings, activity.

Components: delete chat-pane/ (13 files, 1938 lines) and
notes-pane/ (10 files, 2381 lines).

main.go: remove stale Health.Prune maintenance goroutine.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/js/sw/sdk/auth.js

@@ -1,5 +1,5 @@
 // ==========================================
-// Chat Switchboard — SDK: Auth Module
+// Switchboard Core — SDK: Auth Module
 // ==========================================
 // Owns token storage, login/logout/refresh lifecycle,
 // and the permissions/teams/policies cache.

src/js/sw/sdk/can.js

@@ -1,5 +1,5 @@
 // ==========================================
-// Chat Switchboard — SDK: RBAC Gate
+// Switchboard Core — SDK: RBAC Gate
 // ==========================================
 // Synchronous permission checking for render paths.
 //

src/js/sw/sdk/events.js

@@ -1,5 +1,5 @@
 // ==========================================
-// Chat Switchboard — SDK: Event Bus
+// Switchboard Core — SDK: Event Bus
 // ==========================================
 // Labeled event bus with WebSocket bridge.
 // Port of events.js as ES module with factory pattern.

src/js/sw/sdk/pipe.js

@@ -1,5 +1,5 @@
 // ==========================================
-// Chat Switchboard — SDK: Pipe/Filter Pipeline
+// Switchboard Core — SDK: Pipe/Filter Pipeline
 // ==========================================
 // Three-stage pipeline: pre-send, stream, render.
 // Verbatim port of switchboard-sdk.js pipe code.

src/js/sw/sdk/rest-client.js

@@ -1,5 +1,5 @@
 // ==========================================
-// Chat Switchboard — SDK: REST Client
+// Switchboard Core — SDK: REST Client
 // ==========================================
 // Internal HTTP engine for the new SDK.
 // All domain clients and auth module use this.

src/js/sw/sdk/theme.js

@@ -1,5 +1,5 @@
 // ==========================================
-// Chat Switchboard — SDK: Theme Control
+// Switchboard Core — SDK: Theme Control
 // ==========================================
 // Theme management: localStorage + data-theme + system pref.
 // Port of Theme from ui-primitives.js as ES module.