fix(game): restore effect-seven multiball spawn

Use the exact record 148 spawn point and the reconstructed 0.8 * 3800 millipixel velocity for ball slot two. This removes the guessed shooter-lane launch and keeps the multiball lifecycle tied to the recovered effect-seven path.

Test Plan:
- cargo test --all-targets
- cargo clippy --all-targets --all-features -- -D warnings
- rumdl check CHANGELOG.md RECONSTRUCTION.md README.md
- git diff --check

tdkpin-rs/src/game.rs

@@ -1155,8 +1155,8 @@ impl Game {
                     }
                     7 => {
                         self.secondary_ball = Some(Ball {
-                            position: LAUNCHER_POSITION,
-                            velocity: vec2(0.0, -300.0),
+                            position: vec2(17.0, 23.0),
+                            velocity: MilliVec { x: 0, y: 3_040 }.to_velocity_per_second(),
                             in_launcher: false,
                             spin: Real48::ZERO,
                         });
@@ -1844,14 +1844,17 @@ mod tests {
         let spawned = game
             .secondary_ball
             .expect("effect seven should spawn a second ball");
-        assert_eq!(spawned.position, LAUNCHER_POSITION);
-        assert_eq!(spawned.velocity, vec2(0.0, -300.0));
+        assert_eq!(spawned.position, vec2(17.0, 23.0));
+        assert_eq!(
+            MilliVec::from_velocity_per_second(spawned.velocity),
+            MilliVec { x: 0, y: 3_040 }
+        );
 
         game.advance_secondary_ball(&mut events);
         let moving_ball = game
             .secondary_ball
             .expect("second ball should remain active");
-        assert!(moving_ball.position.y < spawned.position.y);
+        assert!(moving_ball.position.y > spawned.position.y);
 
         let balls_before = game.player().balls;
         game.drain(&mut events);