feat(engine): opt Profile / Leaderboard / Home into scrim-click dismiss

Follow-up to a54201e. The previous commit added ScrimDismissible to
Stats, Achievements, and Help; this one extends the same one-line
opt-in to the remaining three read-only modals so the click-outside-
to-close gesture is consistent across every informational surface.

Each modal now has the same shape: capture the scrim from
spawn_modal, attach ScrimDismissible after the build closure
returns. Three lines per file plus the import; no behaviour change
to the modal content itself.

Settings, Onboarding, Pause, Forfeit confirm, ConfirmNewGame, and
the win/game-over modals continue to opt OUT — all carry unsaved
or destructive state where an accidental scrim click would lose
work.

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

solitaire_engine/src/home_plugin.rs

@@ -26,6 +26,7 @@ use crate::progress_plugin::ProgressResource;
 use crate::ui_focus::{Disabled, FocusGroup, Focusable};
 use crate::ui_modal::{
     spawn_modal, spawn_modal_actions, spawn_modal_button, spawn_modal_header, ButtonVariant,
+    ScrimDismissible,
 };
 use crate::ui_theme::{
     ACCENT_PRIMARY, BG_ELEVATED_HI, BORDER_STRONG, BORDER_SUBTLE, RADIUS_MD, STATE_INFO,
@@ -359,7 +360,7 @@ fn handle_home_digit_keys(
 
 /// Spawns the Home modal with five mode cards plus a Cancel button.
 fn spawn_home_screen(commands: &mut Commands, level: u32, font_res: Option<&FontResource>) {
-    spawn_modal(commands, HomeScreen, Z_MODAL_PANEL, |card| {
+    let scrim = spawn_modal(commands, HomeScreen, Z_MODAL_PANEL, |card| {
         spawn_modal_header(card, "Choose a Mode", font_res);
 
         for mode in [
@@ -383,6 +384,8 @@ fn spawn_home_screen(commands: &mut Commands, level: u32, font_res: Option<&Font
             );
         });
     });
+    // Home is read-only — opt into click-outside-to-dismiss.
+    commands.entity(scrim).insert(ScrimDismissible);
 }
 
 /// Tab-walk order for each mode card, matching the visual top-to-bottom