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/ChatPanel.jsx

@@ -0,0 +1,35 @@
+import { useEffect, useRef } from 'react'
+import MessageBubble from './MessageBubble'
+import ThinkingIndicator from './ThinkingIndicator'
+
+export default function ChatPanel({ messages, isLoading, onReplay }) {
+  const bottomRef = useRef(null)
+
+  useEffect(() => {
+    bottomRef.current?.scrollIntoView({ behavior: 'smooth' })
+  }, [messages, isLoading])
+
+  if (messages.length === 0 && !isLoading) {
+    return (
+      <div className="flex-1 flex items-center justify-center">
+        <div className="text-center">
+          <div className="w-16 h-16 rounded-full bg-indigo-600/20 flex items-center justify-center mx-auto mb-4">
+            <span className="text-indigo-400 text-2xl">AI</span>
+          </div>
+          <h2 className="text-xl font-medium text-gray-200 mb-2">Hi, I'm Aria</h2>
+          <p className="text-gray-500 text-sm">Type a message or press the mic to talk</p>
+        </div>
+      </div>
+    )
+  }
+
+  return (
+    <div className="flex-1 overflow-y-auto py-4">
+      {messages.map((msg) => (
+        <MessageBubble key={msg.id} message={msg} onReplay={onReplay} />
+      ))}
+      {isLoading && <ThinkingIndicator />}
+      <div ref={bottomRef} />
+    </div>
+  )
+}