fix(android): correct physical→logical px conversion for safe-area insets

`WindowInsets.getInsets(systemBars())` returns physical pixels (e.g. 84 px
on a 2.625× Pixel 7) but both Bevy's `Val::Px` (UI layer) and the world-
space layout coordinate system use logical pixels. Dividing by
`window.scale_factor()` before applying gives the correct 32 dp offset.

- `safe_area.rs::apply_safe_area_anchors`: query `Window`, divide `insets.top`
  by `scale_factor()` before writing `Val::Px(base_top + top_logical)`.
- `layout.rs::compute_layout`: new `safe_area_top: f32` parameter (logical px)
  subtracts from the vertical budget (`card_width_height_based`) and from
  `top_y` so both card sizing and pile positioning honour the status-bar band.
- `table_plugin.rs`: `setup_table` and `on_window_resized` now read
  `SafeAreaInsets` and divide by scale before passing `safe_area_top` to
  `compute_layout`. New `on_safe_area_changed` system fires a synthetic
  `WindowResized` when insets arrive (~frame 2-3 on Android) so the full
  resize pipeline (layout → pile markers → card snap) re-runs automatically.
- All test call-sites updated with `, 0.0` safe_area_top (desktop/no inset).
- Two regression tests added: shift amount equals `safe_area_top` exactly;
  horizontal layout is unaffected by vertical inset.

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

solitaire_engine/src/safe_area.rs

@@ -71,13 +71,19 @@ impl Plugin for SafeAreaInsetsPlugin {
 /// a session.
 fn apply_safe_area_anchors(
     insets: Res<SafeAreaInsets>,
+    windows: Query<&Window>,
     mut q: Query<(&SafeAreaAnchoredTop, &mut Node)>,
 ) {
     if !insets.is_changed() {
         return;
     }
+    // Android's WindowInsets API returns physical pixels; Bevy UI's Val::Px
+    // expects logical pixels (≈ dp). Divide by the window scale factor so
+    // the HUD band shifts by the correct number of dp on high-DPI devices.
+    let scale = windows.iter().next().map_or(1.0, |w| w.scale_factor());
+    let top_logical = insets.top / scale;
     for (anchor, mut node) in &mut q {
-        node.top = Val::Px(anchor.base_top + insets.top);
+        node.top = Val::Px(anchor.base_top + top_logical);
     }
 }