fix(input): adaptive drop zones, touch event correctness, modal lifecycle guards

H-3:  cursor_plugin drop_overlay_rect and card_centre_for_index now use
      layout.tableau_fan_frac instead of the static TABLEAU_FAN_FRAC constant,
      so drop zones match the actual card fan on portrait Android.
      Removed now-unused TABLEAU_FAN_FRAC import.

H-4:  touch_end_drag uncommitted-tap branch no longer writes StateChangedEvent.
      The mouse path (end_drag) already omits this event for uncommitted drags;
      the touch path now matches, preventing double-animation on valid taps.

H-6:  update_selection_highlight is now gated with run_if(resource_changed)
      on SelectionState | KeyboardDragState | GameStateResource, eliminating
      the unconditional every-frame despawn+respawn of highlight sprites.

H-7:  toggle_home_screen (M-key) now checks other_modal_scrims.is_empty()
      before spawning the home screen, preventing a second concurrent ModalScrim
      when another overlay is already open.

H-8:  spawn_mode_card now inserts ModalButton(ButtonVariant::Secondary) so
      paint_modal_buttons applies hover/press colour feedback on Android.

H-10: auto_resume_on_overlay excludes ForfeitConfirmScreen from its
      "other scrims" query via NonPauseFamilyScrim type alias. Opening the
      forfeit confirm no longer immediately despawns its parent pause modal.
      Also guards paused.0 assignment with an if-check to suppress spurious
      change-detection writes (L-15).

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

solitaire_engine/src/pause_plugin.rs

@@ -437,10 +437,15 @@ fn close_forfeit_modal(
 /// The player reaches these overlays via the HUD menu while paused, which
 /// causes both the pause modal and the overlay to be live simultaneously.
 /// That is always unintentional — the overlay should own the screen.
+/// Query filter for modals that are not part of the pause flow.
+/// Excludes both `PauseScreen` (the pause modal itself) and
+/// `ForfeitConfirmScreen` (spawned from within the pause flow).
+type NonPauseFamilyScrim = (With<ModalScrim>, Without<PauseScreen>, Without<ForfeitConfirmScreen>);
+
 fn auto_resume_on_overlay(
     mut commands: Commands,
     pause_screens: Query<Entity, With<PauseScreen>>,
-    other_modal_scrims: Query<Entity, (With<ModalScrim>, Without<PauseScreen>)>,
+    other_modal_scrims: Query<Entity, NonPauseFamilyScrim>,
     mut paused: ResMut<PausedResource>,
 ) {
     if pause_screens.is_empty() || other_modal_scrims.is_empty() {
@@ -449,7 +454,9 @@ fn auto_resume_on_overlay(
     for entity in &pause_screens {
         commands.entity(entity).despawn();
     }
-    paused.0 = false;
+    if paused.0 {
+        paused.0 = false;
+    }
 }
 
 /// Spawns the pause modal using the standard `ui_modal` scaffold —