fix(engine): Esc dismisses the topmost modal when Profile stacks on Home

Clicking the new Home header chip opens Profile on top of Home.
Pressing Esc then closed Home (because handle_home_cancel_button
fired on Esc with no awareness of layered modals) and left Profile
orphaned over the game — the player had to press P afterwards just
to dismiss what they meant to dismiss in the first place.

Two changes restore the standard "Esc closes the topmost modal"
contract:

- profile_plugin: split P/button (toggle) from Esc (close-only).
  Esc only fires when Profile is currently open.
- home_plugin: handle_home_cancel_button now skips its Esc branch
  when any other ModalScrim exists, deferring to whichever modal
  is on top. Click on the explicit Cancel button is unaffected.

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

solitaire_engine/src/profile_plugin.rs

@@ -146,7 +146,17 @@ fn toggle_profile_screen(
     screens: Query<Entity, With<ProfileScreen>>,
 ) {
     let button_clicked = requests.read().count() > 0;
-    if !keys.just_pressed(KeyCode::KeyP) && !button_clicked {
+    let p_pressed = keys.just_pressed(KeyCode::KeyP);
+    let esc_pressed = keys.just_pressed(KeyCode::Escape);
+    let already_open = !screens.is_empty();
+    // P / button toggles open-or-close. Esc only ever closes — when
+    // Profile is layered over Home (clicking the new Home stats chip
+    // opens this on top), Esc must dismiss the *topmost* modal.
+    // Without this branch, Esc fell through to Home's cancel handler
+    // and closed the wrong modal.
+    let want_open = !already_open && (p_pressed || button_clicked);
+    let want_close = already_open && (p_pressed || button_clicked || esc_pressed);
+    if !want_open && !want_close {
         return;
     }
     if let Ok(entity) = screens.single() {