rebrand: rename VoiceBox to TalkBox throughout codebase

- All 'voicebox'/'Voicebox'/'VOICEBOX' strings replaced with 'talkbox'/'TalkBox'/'TALKBOX'
- Port changed from 17493 to 17494 (avoids conflict with upstream VoiceBox)
- MCP tool namespace: voicebox.* -> talkbox.*
- App bundle ID: sh.voicebox.app -> com.talkbox.app
- Binary names: voicebox-server -> talkbox-server, voicebox-mcp -> talkbox-mcp
- Docker user/group: voicebox -> talkbox
- Database: voicebox.db -> talkbox.db
- Env vars: VOICEBOX_* -> TALKBOX_*
- Asset files renamed: voicebox-logo.* -> talkbox-logo.*, etc.
- External binaries in tauri.conf.json updated to talkbox-server/talkbox-mcp

app/src/components/ServerTab/CloudSection.tsx

@@ -27,7 +27,7 @@ export function CloudSection() {
     if (connected && polling) {
       setPolling(false);
       toast({
-        title: 'Connected to Voicebox Cloud',
+        title: 'Connected to TalkBox Cloud',
         description: `Linked as ${status?.device_name ?? 'this device'}.`,
       });
     }
@@ -84,7 +84,7 @@ export function CloudSection() {
 
   return (
     <SettingSection
-      title="Voicebox Cloud"
+      title="TalkBox Cloud"
       description="End-to-end encrypted backup & sync across your devices."
     >
       <SettingRow
@@ -138,7 +138,7 @@ export function CloudSection() {
         >
           <a
             className="text-sm text-accent hover:underline"
-            href={status?.dashboard_url ?? 'https://voicebox.sh/account'}
+            href={status?.dashboard_url ?? 'https://talkbox.sh/account'}
             rel="noopener noreferrer"
             target="_blank"
           >