feat: unified HomeAI dashboard — merge character + desktop into single app

Combines homeai-character (service status, character profiles, editor) and
homeai-desktop (chat with voice I/O) into homeai-dashboard on port 5173.

- 4-page sidebar layout: Dashboard, Chat, Characters, Editor
- Merged Vite middleware: health checks, service restart, bridge proxy
- Bridge upgraded to ThreadingHTTPServer (fixes LAN request queuing)
- TTS strips emojis before synthesis
- Updated start.sh with new launchd service names
- Added preload-models to startup sequence

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

homeai-dashboard/public/manifest.json

@@ -0,0 +1,16 @@
+{
+  "name": "HomeAI Dashboard",
+  "short_name": "HomeAI",
+  "description": "HomeAI dashboard — services, chat, and character management",
+  "start_url": "/",
+  "display": "standalone",
+  "background_color": "#030712",
+  "theme_color": "#030712",
+  "icons": [
+    {
+      "src": "/icon.svg",
+      "sizes": "any",
+      "type": "image/svg+xml"
+    }
+  ]
+}