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/tests/test_personality_samples.py

@@ -177,7 +177,7 @@ def score(
 # ── Runner ────────────────────────────────────────────────────────────
 
 
-DEFAULT_PORTS = (8000, 8765, 8899, 17493)
+DEFAULT_PORTS = (8000, 8765, 8899, 17494)
 THROWAWAY_PROFILE_PREFIX = "personality-harness-"
 KOKORO_PROBE_VOICE = "af_heart"
 """Any valid kokoro voice id works — compose never calls into TTS, it
@@ -204,7 +204,7 @@ def detect_backend_port(hint: Optional[int]) -> int:
         except Exception:
             continue
     raise SystemExit(
-        "No running Voicebox backend found. Start it (`python backend/main.py`) "
+        "No running TalkBox backend found. Start it (`python backend/main.py`) "
         f"or pass --port. Tried: {candidates}"
     )