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/src/components/ThinkingIndicator.jsx

@@ -0,0 +1,14 @@
+export default function ThinkingIndicator() {
+  return (
+    <div className="flex items-start gap-3 px-4 py-3">
+      <div className="w-8 h-8 rounded-full bg-indigo-600/20 flex items-center justify-center shrink-0">
+        <span className="text-indigo-400 text-sm">AI</span>
+      </div>
+      <div className="flex items-center gap-1 pt-2.5">
+        <span className="w-2 h-2 rounded-full bg-gray-400 animate-[bounce_1.4s_ease-in-out_infinite]" />
+        <span className="w-2 h-2 rounded-full bg-gray-400 animate-[bounce_1.4s_ease-in-out_0.2s_infinite]" />
+        <span className="w-2 h-2 rounded-full bg-gray-400 animate-[bounce_1.4s_ease-in-out_0.4s_infinite]" />
+      </div>
+    </div>
+  )
+}