chore(todo): add acceptance criteria and test hints to open issues

Flesh out the 14 still-open issues (GAL-34/35/36/37, 40/41, 43, 46/47/48/49,
52/53/55) with explicit acceptance criteria and concrete integration test
hints that reference existing types and headless tooling, so future work
on these tickets has a clear definition of done.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

TODO/GAL-34.md

@@ -15,3 +15,14 @@ Allow the player to rescue a captured ship and operate in dual-fighter mode.
 - [ ] [GAL-35](GAL-35.md) — Allow the player to shoot a Boss that is holding a captured ship.
 - [ ] [GAL-36](GAL-36.md) — Implement the logic to free the captured ship upon shooting the Boss.
 - [ ] [GAL-37](GAL-37.md) — Implement the dual fighter mode (controlling two ships, firing two bullets).
+
+## Acceptance criteria
+
+- [ ] End-to-end Galaga rescue flow works: capture → shoot Boss in `ReturningWithCaptive` → freed ship attaches → dual fighter active.
+- [ ] Losing the side ship of a dual fighter does **not** subtract a life and does **not** trigger respawn.
+- [ ] Score reflects rescue bonus distinct from a normal Boss kill.
+
+## Integration test hints
+
+- Scripted scenario test (`tests/dual_fighter.rs`): build a minimal `App`, advance through capture → rescue → side-fighter-loss; assert state and resource values at each step.
+- Audit no regressions in `tests/special_stage.rs` style: keep tests deterministic by injecting `Time` and `fastrand` seeds.