fix(ux): 14 cross-platform UX/UI fixes from 500-game audit

Web client (game.js):
- Restart game timer after undo exits auto-complete sequence
- Pause timer while browser tab is hidden (visibilitychange)
- Validate URL seed — NaN / negative falls back to randomSeed()
- Guard onBoardClick/onBoardDblClick during win (snap.is_won)
- Delay win overlay 320 ms so last card CSS transition finishes
- Force reflow in flashIllegal() to restart shake on rapid re-trigger

Android (safe_area.rs):
- Preserve last-known insets on app resume instead of zeroing them;
  eliminates double layout flash on every foreground cycle

All clients — Bevy engine:
- Radial menu: clamp icon anchors to viewport bounds so icons are
  never placed off-screen on narrow phones
- Auto-complete: deactivate state.active when is_auto_completable
  goes false (undo mid-sequence) to stop perpetual background retry
- Touch selection: gate highlight rebuild on is_changed() — was
  despawning/respawning entities every frame unnecessarily
- Input: fire "Tap a pile to move" InfoToast on first tap in
  TapToSelect mode; document cursor_world 1:1 viewport invariant
- Drag threshold: raise desktop from 4 → 6 px to prevent accidental
  drags from cursor jitter on HiDPI displays

Desktop / Android (solitaire_app):
- Call cleanup_orphaned_tmp_files() at startup to remove .tmp files
  left by crashes between atomic write and rename

Design clarification (klondike_adapter.rs):
- Doc comment: Draw-1 recycling is penalty-only by design (never
  blocked) to avoid creating unwinnable positions

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

solitaire_engine/src/safe_area.rs

@@ -253,24 +253,24 @@ mod android {
         }
     }
 
-    /// Resets the inset poller and clears cached insets on
-    /// `AppLifecycle::WillResume` so that `refresh_insets` re-queries JNI in the
-    /// frames immediately after the app returns to the foreground.
+    /// Resets the inset poller on `AppLifecycle::WillResume` so that
+    /// `refresh_insets` re-queries JNI in the frames immediately after the app
+    /// returns to the foreground.
     ///
-    /// Clearing `SafeAreaInsets` to the default (all-zero) fires
-    /// `on_safe_area_changed` in `table_plugin`, which emits a synthetic
-    /// `WindowResized`.  `on_window_resized` then recomputes the layout;
-    /// once `refresh_insets` resolves the real values a second synthetic
-    /// `WindowResized` fires and the layout converges to the correct position.
+    /// The cached `SafeAreaInsets` are intentionally **not** zeroed here.
+    /// Zeroing them would cause two layout recomputes on every resume:
+    /// once with zero insets (wrong position) and again when JNI resolves the
+    /// real values — visible as a flash.  By preserving the last-known values
+    /// the layout remains stable; if JNI returns a different value (e.g. after
+    /// a rotation) the single update that fires when `SafeAreaInsets` actually
+    /// changes is enough.
     pub(super) fn rearm_on_resumed(
         mut lifecycle: MessageReader<AppLifecycle>,
         mut poll: ResMut<SafeAreaPollTries>,
-        mut insets: ResMut<SafeAreaInsets>,
     ) {
         for event in lifecycle.read() {
             if matches!(event, AppLifecycle::WillResume) {
                 poll.0 = 0;
-                *insets = SafeAreaInsets::default();
             }
         }
     }