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_app/src/lib.rs

@@ -25,7 +25,10 @@ use bevy::window::{MonitorSelection, PresentMode, WindowPosition};
 use bevy::winit::WinitWindows;
 #[cfg(target_os = "android")]
 use bevy::winit::{UpdateMode, WinitSettings};
-use solitaire_data::{Settings, load_settings_from, provider_for_backend, settings_file_path};
+use solitaire_data::{
+    Settings, cleanup_orphaned_tmp_files, load_settings_from, provider_for_backend,
+    settings_file_path,
+};
 use solitaire_engine::{CoreGamePlugin, SyncProvider, register_theme_asset_sources};
 
 fn load_settings() -> Settings {
@@ -49,6 +52,12 @@ pub fn run() {
     // and any debugger attached still sees the panic).
     install_crash_log_hook();
 
+    // Remove any *.tmp files left behind by a crash between an atomic write
+    // and its rename.  Safe to call unconditionally — missing data dir is a
+    // no-op.  Must run before GamePlugin loads saved state so orphaned files
+    // don't accumulate across launches.
+    let _ = cleanup_orphaned_tmp_files();
+
     // Initialise the platform keyring store before any token operations.
     // On Linux this uses the Secret Service (GNOME Keyring / KWallet); on
     // macOS it uses the Keychain; on Windows it uses the Credential store.