fix: apply ruff auto-fixes and add hk git hooks

- Fix pre-existing lint errors in engine/ modules using ruff --unsafe-fixes
- Add hk.pkl with pre-commit and pre-push hooks using ruff builtin
- Configure hooks to use 'uv run' prefix for tool execution
- Update mise.toml to include hk and pkl tools
- All 73 tests pass

fix: apply ruff auto-fixes and add hk git hooks

- Fix pre-existing lint errors in engine/ modules using ruff --unsafe-fixes
- Add hk.pkl with pre-commit and pre-push hooks using ruff builtin
- Configure hooks to use 'uv run' prefix for tool execution
- Update mise.toml to include hk and pkl tools
- Use 'hk install --mise' for proper mise integration
- All 73 tests pass

engine/mic.py

@@ -8,6 +8,7 @@ import atexit
 try:
     import numpy as _np
     import sounddevice as _sd
+
     _HAS_MIC = True
 except Exception:
     _HAS_MIC = False
@@ -40,12 +41,15 @@ class MicMonitor:
         """Start background mic stream. Returns True on success, False/None otherwise."""
         if not _HAS_MIC:
             return None
+
         def _cb(indata, frames, t, status):
-            rms = float(_np.sqrt(_np.mean(indata ** 2)))
+            rms = float(_np.sqrt(_np.mean(indata**2)))
             self._db = 20 * _np.log10(rms) if rms > 0 else -99.0
+
         try:
             self._stream = _sd.InputStream(
-                callback=_cb, channels=1, samplerate=44100, blocksize=2048)
+                callback=_cb, channels=1, samplerate=44100, blocksize=2048
+            )
             self._stream.start()
             atexit.register(self.stop)
             return True