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

backend/models.py

@@ -309,7 +309,7 @@ class GenerationSettingsUpdate(BaseModel):
 
 class MCPClientBindingResponse(BaseModel):
     """Per-MCP-client voice binding — what voice / engine the server should
-    use when a given client_id calls voicebox.speak without args, plus an
+    use when a given client_id calls talkbox.speak without args, plus an
     opt-in personality-rewrite default."""
 
     client_id: str
@@ -346,7 +346,7 @@ class MCPClientBindingListResponse(BaseModel):
 
 
 class SpeakRequest(BaseModel):
-    """Body for POST /speak — non-MCP REST surface that mirrors voicebox.speak."""
+    """Body for POST /speak — non-MCP REST surface that mirrors talkbox.speak."""
 
     text: str = Field(..., min_length=1, max_length=10000)
     profile: Optional[str] = Field(
@@ -807,7 +807,7 @@ class CloudLoginStartResponse(BaseModel):
 
 
 class CloudStatusResponse(BaseModel):
-    """Current link between this device and a Voicebox Cloud account."""
+    """Current link between this device and a TalkBox Cloud account."""
 
     connected: bool
     device_name: Optional[str] = None