feat(engine): playability improvements — rounds 7–9 (#40–#64)

Round 7 — Input & feedback
- H key cycles hints; F1 opens help (conflict resolved)
- N key cancels active Time Attack session
- Hint text distinguishes "draw from stock" vs "recycle waste"
- Forfeit (G) clears AutoCompleteState so chime does not bleed into new deal
- Zen mode timer clears immediately on Z press
- HUD shows recycle count in both draw modes
- Settings scroll position persisted across open/close

Round 8 — Polish & clarity
- Undo unavailable fires "Nothing to undo" toast
- Streak-break toast on forfeit/abandon when streak > 1
- F11 fullscreen toggle with toast; documented in help and home screens
- H-after-win, new-game countdown expiry, Tab-no-cards toasts
- Win cascade duration/stagger scales with animation speed setting
- Draw-Three cycle counter HUD ("Cycle: N/3")
- Forfeit requires G×2 confirmation within 3 s (mirrors N key)

Round 9 — Game feel & information
- Escape dismisses game-over/stuck overlay (PausePlugin skips Escape when overlay visible)
- Shake animation on rejected drag before snap-back
- Forfeit countdown cancels when any other key is pressed (U/H/D/Z/Space)
- Tab wrap-around fires "Back to first card" toast
- HUD selection indicator shows active Tab-selected pile in yellow
- Challenge time-limit HUD turns orange < 60s, red < 30s
- Win summary shows XP breakdown (+50 base, +25 no-undo, +N speed)
- Game-over overlay: "No more moves available" with clear N/Escape/G instructions

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

solitaire_engine/src/daily_challenge_plugin.rs

@@ -18,7 +18,7 @@ use chrono::{Local, NaiveDate};
 use solitaire_data::{daily_seed_for, save_progress_to};
 use solitaire_sync::ChallengeGoal;
 
-use crate::events::{GameWonEvent, NewGameRequestEvent, XpAwardedEvent};
+use crate::events::{GameWonEvent, InfoToastEvent, NewGameRequestEvent, XpAwardedEvent};
 use crate::game_plugin::GameMutation;
 use crate::progress_plugin::{ProgressResource, ProgressStoragePath, ProgressUpdate};
 use crate::resources::GameStateResource;
@@ -143,6 +143,7 @@ fn poll_server_challenge(
     }
 }
 
+#[allow(clippy::too_many_arguments)]
 fn handle_daily_completion(
     mut wins: EventReader<GameWonEvent>,
     daily: Res<DailyChallengeResource>,
@@ -151,6 +152,7 @@ fn handle_daily_completion(
     path: Res<ProgressStoragePath>,
     mut completed: EventWriter<DailyChallengeCompletedEvent>,
     mut xp_awarded: EventWriter<XpAwardedEvent>,
+    mut toast: EventWriter<InfoToastEvent>,
 ) {
     for ev in wins.read() {
         if game.0.seed != daily.seed {
@@ -182,6 +184,7 @@ fn handle_daily_completion(
             date: daily.date,
             streak: progress.0.daily_challenge_streak,
         });
+        toast.send(InfoToastEvent("Daily challenge complete! +100 XP".to_string()));
     }
 }