fix(engine): Draw-Three waste fan hit-testing; add HUD and input coverage

fix(input_plugin): card_position() now applies the same X-fan offset for
Draw-Three waste cards as card_plugin uses for rendering. Previously the
top waste card appeared at base_x + 0.56 * card_width but was only
hittable at base_x, making it impossible to drag from its visual position.

test(hud_plugin): add five behaviour tests — score/moves/time display
format, Zen mode score suppression, Draw-Three mode badge.

test(input_plugin): add find_draggable test that clicks the top fanned
waste card at its visual X position and confirms it hits in Draw-Three.

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

solitaire_engine/src/input_plugin.rs

@@ -23,6 +23,7 @@ use solitaire_core::pile::PileType;
 use solitaire_core::rules::{can_place_on_foundation, can_place_on_tableau};
 
 use crate::card_plugin::{CardEntity, TABLEAU_FAN_FRAC};
+use solitaire_core::game_state::DrawMode;
 use crate::challenge_plugin::CHALLENGE_UNLOCK_LEVEL;
 use crate::events::{
     DrawRequestEvent, InfoToastEvent, MoveRejectedEvent, MoveRequestEvent, NewGameConfirmEvent,
@@ -341,8 +342,15 @@ fn card_position(game: &GameState, layout: &Layout, pile: PileType, stack_index:
     if matches!(pile, PileType::Tableau(_)) {
         let fan = -layout.card_size.y * TABLEAU_FAN_FRAC;
         Vec2::new(base.x, base.y + fan * (stack_index as f32))
+    } else if matches!(pile, PileType::Waste) && game.draw_mode == DrawMode::DrawThree {
+        // In Draw-Three mode the top 3 waste cards are fanned in X to match
+        // card_plugin::card_positions(). Hit-testing must use the same offsets
+        // so clicking the visually rightmost (top) card actually registers.
+        let pile_len = game.piles.get(&pile).map_or(0, |p| p.cards.len());
+        let visible_start = pile_len.saturating_sub(3);
+        let slot = stack_index.saturating_sub(visible_start) as f32;
+        Vec2::new(base.x + slot * layout.card_size.x * 0.28, base.y)
     } else {
-        let _ = game;
         base
     }
 }
@@ -645,6 +653,31 @@ mod tests {
         );
     }
 
+    #[test]
+    fn find_draggable_draw_three_waste_top_card_hit_at_fanned_position() {
+        use solitaire_core::card::{Card, Rank, Suit};
+        use solitaire_core::game_state::{DrawMode, GameMode};
+        let mut game = GameState::new_with_mode(1, DrawMode::DrawThree, GameMode::Classic);
+        let waste = game.piles.get_mut(&PileType::Waste).unwrap();
+        waste.cards.clear();
+        // Three waste cards; top (id=202) is rightmost in the fan.
+        waste.cards.push(Card { id: 200, suit: Suit::Spades, rank: Rank::Two, face_up: true });
+        waste.cards.push(Card { id: 201, suit: Suit::Hearts, rank: Rank::Three, face_up: true });
+        waste.cards.push(Card { id: 202, suit: Suit::Clubs, rank: Rank::Four, face_up: true });
+
+        let layout = compute_layout(Vec2::new(1280.0, 800.0));
+        let waste_base = layout.pile_positions[&PileType::Waste];
+        // Top card (slot=2) is at base.x + 2 * 0.28 * card_width.
+        let top_card_x = waste_base.x + 2.0 * 0.28 * layout.card_size.x;
+        let cursor = Vec2::new(top_card_x, waste_base.y);
+
+        let result = find_draggable_at(cursor, &game, &layout);
+        assert!(result.is_some(), "top fanned waste card must be hittable at its visual X position");
+        let (pile, _start, ids) = result.unwrap();
+        assert_eq!(pile, PileType::Waste);
+        assert_eq!(ids, vec![202], "only the top card is draggable from waste");
+    }
+
     #[test]
     fn pile_drop_rect_is_card_sized_for_non_tableau() {
         let game = GameState::new(42, DrawMode::DrawOne);