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>

docs/ROADMAP.md

@@ -61,9 +61,11 @@ Ubuntu + NVIDIA first; `.deb` distribution (see `DECISIONS.md`).
       watcher (Steam RunningAppID + /proc), GameMode hook, and the always-on `systemd --user`
       service.
 - [~] M9 interactive installer — *done:* distro/GPU detection + optional-dependency install
-      (`rigdoctor install`, GUI Setup tab); **user-local `install.sh` + self-extracting `.run`**
-      (no-root venv install, handles python3-venv prereq, CI-built). *Pending:* module-selection
-      config + `systemd --user` service enable + trigger-mode pick.
+      (`rigdoctor install`, GUI Settings); **user-local `install.sh` + self-extracting `.run`**
+      (no-root venv install, handles python3-venv prereq, CI-built); **`systemd --user` trigger
+      modes** (`core/service.py`, `rigdoctor service mode manual|always-on|game-launch` + GUI
+      Settings "Recording trigger") incl. the zero-config **game-launch watcher**
+      (`core/watcher.py`, `rigdoctor watch`). *Pending:* module-selection config during install.
 - [ ] `.deb` packaging (D8) declaring per-bundle deps incl. python3-pyside6 for Desktop UI
 
 ## Phase 5 — Breadth (later)