chore(todo): add GAL-56 — Score resource does not reset on game restart

TODO/GAL-50.md

@@ -17,3 +17,4 @@ Score, lives, stage, high-score, start menu, and restart UI.
 - [x] [GAL-53](GAL-53.md) — Implement a High Score system (saving/loading).
 - [x] [GAL-54](GAL-54.md) — Create a Start Menu state with a "Start Game" button.
 - [ ] [GAL-55](GAL-55.md) — Add a "Press R to Restart" message to the `GameOver` screen and implement restart logic.
+- [ ] [GAL-56](GAL-56.md) — Score resource does not reset on game restart.

TODO/GAL-56.md

@@ -0,0 +1,42 @@
+---
+id: GAL-56
+title: Score resource does not reset on game restart
+status: Todo
+parent: GAL-50
+labels: [bug, ui]
+---
+
+# GAL-56: Score resource does not reset on game restart
+
+The `restart_game_system` in `src/game_state.rs` only resets `RestartPressed` and transitions to `Playing`. It does not reset `Score`, `PlayerLives`, `CurrentStage`, or `FormationState` resources.
+
+This means on subsequent games after the first, `Score` retains the previous game's final score. The Game Over screen shows the cumulative total ("Your Score") rather than the current game's score, and `check_high_score` (from GAL-53) compares against the accumulated score instead of the current game's score.
+
+## Acceptance criteria
+
+- [ ] Restarting from `GameOver` resets `Score.value` to 0.
+- [ ] Restarting resets `PlayerLives.count` to starting value.
+- [ ] Restarting resets `CurrentStage.number` to 1.
+- [ ] Restarting resets `FormationState` to default.
+- [ ] Restarting despawns all `Enemy`, `Bullet`, `EnemyBullet`, `Explosion`, and `TractorBeam` entities.
+
+## Code context
+
+**`src/game_state.rs`** (restart system, current state):
+```rust
+pub fn restart_game_system(
+    mut next_state: ResMut<NextState<AppState>>,
+    mut restart: ResMut<RestartPressed>,
+) {
+    if restart.pressed {
+        restart.pressed = false;
+        next_state.set(AppState::Playing);
+    }
+}
+```
+
+No resource reset logic exists. The `cleanup_game_entities` system runs on `OnExit(Playing)` but does not reset resources.
+
+## Integration test hints
+
+- Build `App`, transition to `Playing`, set `Score = 5000`, transition to `GameOver`, restart, assert `Score.value == 0`.