feat(engine): group HUD menu popover into Play/You/Community/System sections

Phase C of docs/ui-redesign-2026-07.md. The Modes row is gone — Home
owns mode selection, so the popover's Play section carries a Home row
firing the new ToggleHomeRequestEvent (read by toggle_home_screen
alongside the existing M accelerator). Section headers are quiet
caption-size labels inside the existing panel widget, not a new
widget. The action-bar Modes button and its popover are untouched
(their removal is Phase B territory when Home gains hierarchy).

- MenuOption: Modes variant replaced by Home; rows grouped Play (Home)
  · You (Profile, Stats, Achievements) · Community (Leaderboard) ·
  System (Settings, Help)
- handle_menu_option_click no longer chains into spawn_modes_popover
- Tests: tooltip sweep updated (7 rows still), new
  toggle_home_event_opens_home_screen covers the popover's open path

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

solitaire_engine/src/home_plugin.rs

@@ -24,7 +24,8 @@ use crate::daily_challenge_plugin::DailyChallengeResource;
 use crate::events::{
     InfoToastEvent, NewGameRequestEvent, StartChallengeRequestEvent,
     StartDailyChallengeRequestEvent, StartDifficultyRequestEvent, StartPlayBySeedRequestEvent,
-    StartTimeAttackRequestEvent, StartZenRequestEvent, ToggleProfileRequestEvent,
+    StartTimeAttackRequestEvent, StartZenRequestEvent, ToggleHomeRequestEvent,
+    ToggleProfileRequestEvent,
 };
 use crate::font_plugin::FontResource;
 use crate::progress_plugin::ProgressResource;
@@ -264,6 +265,7 @@ impl Plugin for HomePlugin {
             .add_message::<StartPlayBySeedRequestEvent>()
             .add_message::<StartDifficultyRequestEvent>()
             .add_message::<InfoToastEvent>()
+            .add_message::<ToggleHomeRequestEvent>()
             .add_message::<ToggleProfileRequestEvent>()
             .add_message::<SettingsChangedEvent>()
             // Defensively register MouseWheel so `scroll_home_panel`
@@ -371,6 +373,7 @@ fn spawn_home_on_launch(
 fn toggle_home_screen(
     mut commands: Commands,
     keys: Res<ButtonInput<KeyCode>>,
+    mut requests: MessageReader<ToggleHomeRequestEvent>,
     progress: Option<Res<ProgressResource>>,
     stats: Option<Res<StatsResource>>,
     settings: Option<Res<SettingsResource>>,
@@ -380,7 +383,8 @@ fn toggle_home_screen(
     other_modal_scrims: Query<(), (With<crate::ui_modal::ModalScrim>, Without<HomeScreen>)>,
     diff_expanded: Res<DifficultyExpanded>,
 ) {
-    if !keys.just_pressed(KeyCode::KeyM) {
+    let button_clicked = requests.read().count() > 0;
+    if !keys.just_pressed(KeyCode::KeyM) && !button_clicked {
         return;
     }
     if let Ok(entity) = screens.single() {
@@ -1621,6 +1625,44 @@ mod tests {
         );
     }
 
+    /// The HUD Menu popover's "Home" row fires
+    /// `ToggleHomeRequestEvent`; it must open Home exactly like the
+    /// `M` accelerator (Phase C: the popover's Play section replaces
+    /// the old Modes row).
+    #[test]
+    fn toggle_home_event_opens_home_screen() {
+        let mut app = headless_app();
+        app.world_mut()
+            .resource_mut::<Messages<ToggleHomeRequestEvent>>()
+            .write(ToggleHomeRequestEvent);
+        app.update();
+
+        assert_eq!(
+            app.world_mut()
+                .query::<&HomeScreen>()
+                .iter(app.world())
+                .count(),
+            1,
+            "ToggleHomeRequestEvent must open the Home modal"
+        );
+
+        // A second request toggles it closed, matching the M key.
+        app.world_mut()
+            .resource_mut::<Messages<ToggleHomeRequestEvent>>()
+            .write(ToggleHomeRequestEvent);
+        app.update();
+        app.update();
+
+        assert_eq!(
+            app.world_mut()
+                .query::<&HomeScreen>()
+                .iter(app.world())
+                .count(),
+            0,
+            "second ToggleHomeRequestEvent must close the Home modal"
+        );
+    }
+
     #[test]
     fn pressing_m_twice_closes_home_screen() {
         let mut app = headless_app();