fix(divergence): reject occupied multiball wheel slots

The original leaves contact owner 2 after either ball fills a wheel hole during
multiball. Once play collapses to one ball, that sentinel permits one more
capture and award in the visibly occupied hole before becoming permanent.

Deliberately replace the completed wheel contact with the permanent 99 sentinel
for both ball slots. This keeps visual occupancy, collision admission, and
scoring consistent: a filled hole cannot consume or reward another ball. The
special reserve hole and claw retain their original contact behavior.

Document `divergence` as the required Conventional Commit scope for future fixes
that intentionally differ from original-game behavior.

Test Plan:
- `just test` -- passed (142 game tests and 8 service tests)
- `just clippy` -- passed
- `just build-production` -- passed
- `cargo +nightly fmt --all -- --check` -- passed
- `rumdl check --flavor commonmark CHANGELOG.md AGENTS.md` -- passed
- `git diff --cached --check` -- passed

tdkpin-rs/src/game.rs

@@ -1747,6 +1747,11 @@ impl Game {
         events: &mut Vec<Event>,
     ) -> BallAction {
         self.wheel_holes[index] = true;
+        // Deliberate original-game divergence: a multiball capture normally
+        // leaves owner 2 here, which lets the surviving single ball capture
+        // the visibly occupied hole once more. Occupied wheel holes remain
+        // permanent in the clone regardless of which ball completed them.
+        self.record_contacts[129 + index] = 99;
         // 1000:967a derives the award from all live type-three contact words,
         // including another ball that is still settling into a lock hole.
         let filled = self.record_contacts[129..=133]
@@ -3450,7 +3455,7 @@ mod tests {
         assert!(game.secondary_ball.is_none());
         assert_eq!(game.score_mode, ScoreMode::Multiball);
         assert_eq!(game.ball.capture_age, 17);
-        assert_eq!(game.record_contacts[usize::from(sensor.id)], 2);
+        assert_eq!(game.record_contacts[usize::from(sensor.id)], 99);
         assert!(game.wheel_holes[0]);
         assert!(events.contains(&Event::Lock));
 
@@ -3538,10 +3543,35 @@ mod tests {
         assert_eq!(game.ball.position, survivor.position);
         assert_eq!(game.ball.velocity, survivor.velocity);
         assert_eq!(game.ball.capture_age, survivor.capture_age);
-        assert_eq!(game.record_contacts[usize::from(sensor.id)], 2);
+        assert_eq!(game.record_contacts[usize::from(sensor.id)], 99);
         assert!(game.wheel_holes[0]);
     }
 
+    #[test]
+    fn occupied_multiball_wheel_hole_rejects_the_surviving_ball() {
+        let sensor = LOCK_HOLES[0];
+        let mut game = Game::new(1);
+        game.ball.in_launcher = false;
+        game.ball.position = sensor.center;
+        game.ball.velocity = Vec2::ZERO;
+        game.ball.capture_age = 300;
+        game.record_contacts[usize::from(sensor.id)] = 99;
+        game.wheel_holes[0] = true;
+        let mut events = Vec::new();
+
+        let action = game.check_sensor_objects(
+            MilliVec::from_position(sensor.center),
+            MilliVec::default(),
+            &mut events,
+        );
+
+        assert_eq!(action, BallAction::Keep);
+        assert_eq!(game.record_contacts[usize::from(sensor.id)], 99);
+        assert_eq!(game.player().secondary_score, 0);
+        assert!(!events.contains(&Event::Lock));
+        assert!(!game.ball.in_launcher);
+    }
+
     #[test]
     fn center_drain_advances_to_a_fresh_ball() {
         let mut game = Game::new(1);