feat(m9): systemd --user trigger modes + game-launch watcher — 0.23.0

D6 trigger modes, no root:
- core/service.py: write/enable `systemd --user` units; apply_mode(manual/
  always-on/game-launch) reconciles the recorder + watcher services; status().
- core/watcher.py + `rigdoctor watch`: poll Steam RunningAppID, auto-bracket a
  focused capture (D12 zero-config fallback; wrapper stays primary).
- CLI `rigdoctor service status|mode`; config `trigger_mode`.
- GUI Settings: "Recording trigger" dropdown (Apply runs apply_mode off-thread).
- Tests for unit generation, mode reconciliation, watcher transitions/parse.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "rigdoctor"
-version = "0.22.0"
+version = "0.23.0"
 description = "Modular hardware monitoring & crash diagnostics for Linux gamers."
 readme = "README.md"
 requires-python = ">=3.11"