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_refinement_samples.py

@@ -15,7 +15,7 @@ Usage:
     python backend/tests/test_refinement_samples.py
 
     # Hit a non-default port (auto-detected via /health probe when omitted):
-    python backend/tests/test_refinement_samples.py --port 17493
+    python backend/tests/test_refinement_samples.py --port 17494
 
     # Only test one model size:
     python backend/tests/test_refinement_samples.py --model 4B
@@ -316,7 +316,7 @@ def score(sample: Sample, model: str, refined: str, latency_ms: int) -> Scorecar
 # ── Runner ────────────────────────────────────────────────────────────
 
 
-DEFAULT_PORTS = (8000, 8765, 8899, 17493)
+DEFAULT_PORTS = (8000, 8765, 8899, 17494)
 
 
 def detect_backend_port(hint: Optional[int]) -> int:
@@ -339,7 +339,7 @@ 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}"
     )
 
@@ -407,7 +407,7 @@ def format_report(cards: list[Scorecard]) -> str:
 def main() -> int:
     ap = argparse.ArgumentParser(description=__doc__)
     ap.add_argument("--port", type=int, default=None,
-                    help="Voicebox backend port (auto-detected if omitted)")
+                    help="TalkBox backend port (auto-detected if omitted)")
     ap.add_argument("--model", choices=("0.6B", "1.7B", "4B"), action="append",
                     help="Refinement model size(s) to test (repeat to run several)")
     ap.add_argument("--json", type=Path, default=None,