refactor(gui): grouped navigation + clearer page names — 0.20.0

Reshape the IA so it reads by intent instead of a flat pile of pages.

- Grouped sidebar: Monitor / Diagnose / System / App (section headers).
- Renames: Health → System Health, Environment → Tuning, Logs → Recordings,
  Setup → Settings.
- Settings absorbs Notifications (alerts) as a section; Notifications dropped as a
  separate page (notifications_page.py removed; SetupPage gains the alerts card +
  `changed` signal wired to the live alert monitor).
- Recordings is now a hub: a source dropdown to view any captured log (always-on /
  last diagnostic / preserved crash) + Analyze-crash in place, plus the recorder
  controls; status line now shows the captured game.
- main_window nav is data-driven (_NAV groups → _PAGES order → stack); show_page,
  badges, and tray flows updated. GUI smoke test asserts the new page set.

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

docs/MODULES.md

@@ -67,12 +67,13 @@ Status: ⬜ not started · 🟦 designing · 🟨 in progress · ✅ done
   (`pending_crash`/`analyze_crash` + `health.check_previous_boot`). *Pending:* non-Steam
   launchers (Lutris/Heroic), GPU power-profile (PowerMizer) checks, and the zero-config watcher.
 - **M8 Alerting** — threshold/event notifications; integrates with the tray applet (M11).
-- **M10 Desktop GUI** — PySide6 graphical front-end over the core engine (dashboard, log
-  browser, report viewer, logger controls). Optional; adds the Qt dependency. *Bootstrapped
-  early (ahead of its Phase 4 slot) at the user's request:* dark-themed window with sidebar
-  nav, a live dashboard (circular gauges + collapsible per-subsystem cards, temperature-
-  colored values), and a **Recording/Logs page** with full M3 controls (start/stop/status +
-  post-crash report). Health/Inventory remain placeholders until M4/M5. GUI-first per D17.
+- **M10 Desktop GUI** — PySide6 graphical front-end over the core engine. Optional; adds the
+  Qt dependency. Dark-themed window with a **grouped sidebar** (Monitor / Diagnose / System /
+  App) over: **Dashboard** (live history graphs + per-subsystem cards), **Games** (M6 detection
+  + Run Diagnostic), **Recordings** (recorder controls + view/report any captured log + analyze
+  a crash), **System Health** (M4 scan), **Tuning** (M6 gaming tunables + fixes), **Inventory**
+  (M5), **Settings** (components/deps + alerts + account + uninstall), and **Share** (M12). A
+  global recording badge shows on every page. GUI-first per D17.
 - **M11 Tray applet** — `QSystemTrayIcon` menu-bar applet. *Implemented (`gui/tray.py`, D13):*
   the menu shows live M1 readouts (CPU temp, GPU temp, memory used/total) + a status line
   (Normal / Hot / GPU not responding), led by a **Run Diagnostic** submenu (per detected game →