fix(physics): restore the one-way shooter exit

Use the recovered rail rebound coefficient and let a launched ball cross object
22 in the exit direction after the upper curve. Strengthen the launch
regression so a momentary lane crossing cannot hide a later rebound.

Test Plan:
- cargo fmt --check
- cargo test
- cargo clippy --all-targets --all-features -- -D warnings
- verify the charged launch trajectory at detail levels 1 through 5

tdkpin-rs/src/game.rs

@@ -9,6 +9,7 @@ const FLIPPER_CONTACT_RADIUS: f32 = 9.0;
 // geometry. A small contact epsilon preserves thin-line hits without adding
 // the rendered ball radius to every recovered boundary.
 const TABLE_LINE_RADIUS: f32 = 1.0;
+const SHOOTER_EXIT_GATE_ID: u8 = 22;
 const GRAVITY: f32 = 135.0;
 const MAX_SPEED: f32 = 430.0;
 const BALL_SEARCH_DELAY: f32 = 3.0;
@@ -263,6 +264,18 @@ impl Game {
 
             let mut drained = false;
             for wall in WALLS {
+                // The upper shooter exit is a one-way gate. After the outer
+                // curve turns the launched ball down and left, object 22 must
+                // let it enter the playfield. A ball approaching from below
+                // still collides with the gate.
+                if wall.id == SHOOTER_EXIT_GATE_ID
+                    && self.ball.velocity.x < 0.0
+                    && self.ball.velocity.y > 0.0
+                    && self.ball.position.x < 290.0
+                    && self.ball.position.y < 35.0
+                {
+                    continue;
+                }
                 // Object 25 is the one-way shooter stop. It catches a returning
                 // ball, but must not reflect an upward launch from the line.
                 if wall.id == 25 && self.ball.velocity.y < 0.0 {
@@ -623,25 +636,32 @@ mod tests {
 
     #[test]
     fn charged_ball_clears_the_shooter_lane() {
-        let mut game = Game::new(1);
-        launch_ball(&mut game, 33);
-        let mut entered_table = false;
-        let mut minimum_y = game.ball.position.y;
+        for detail in 1..=5 {
+            let mut game = Game::new(1);
+            launch_ball(&mut game, 33);
+            let mut entered_table = false;
+            let mut returned_to_launcher = false;
+            let mut minimum_y = game.ball.position.y;
 
-        for _ in 0..240 {
-            game.update(1.0 / 120.0, 5, Controls::default());
-            minimum_y = minimum_y.min(game.ball.position.y);
-            if game.ball.position.x < 298.0 {
-                entered_table = true;
-                break;
+            for _ in 0..240 {
+                game.update(1.0 / 120.0, detail, Controls::default());
+                minimum_y = minimum_y.min(game.ball.position.y);
+                if game.ball.position.x < 280.0 && game.ball.position.y > 30.0 {
+                    entered_table = true;
+                }
+                returned_to_launcher |= game.ball.in_launcher;
             }
-        }
 
-        assert!(
-            entered_table,
-            "the shooter curve should guide the ball onto the table; position={:?}, velocity={:?}, minimum_y={minimum_y}",
-            game.ball.position, game.ball.velocity
-        );
+            assert!(
+                entered_table,
+                "detail {detail}: the shooter curve should guide the ball onto the table; position={:?}, velocity={:?}, minimum_y={minimum_y}",
+                game.ball.position, game.ball.velocity
+            );
+            assert!(
+                !returned_to_launcher,
+                "detail {detail}: a launched ball must not rebound into the launcher"
+            );
+        }
     }
 
     #[test]

tdkpin-rs/src/table.rs

@@ -12,7 +12,10 @@
 use crate::geometry::Segment;
 use macroquad::prelude::Vec2;
 
-const WALL_BOUNCE: f32 = 0.82;
+// The ordinary rail registrations in `FUN_1000_34ab` use the recovered 0.1
+// rebound coefficient. The previous 0.82 value made the shooter curve behave
+// like a rubber bumper and sent the ball back down the launch lane.
+const WALL_BOUNCE: f32 = 0.10;
 
 #[derive(Clone, Copy, Debug)]
 pub struct TableSegment {