chore(simulation): update tests and fixtures for Sprint 23

- Add debug_response: None to all ObserverSnapshot constructors in
  integration tests
- Bump PROTOCOL_VERSION assertion 17 → 18 in serialization tests
- Regenerate golden proof_room_tick_10.json (BoundaryWall tiles)
- Regenerate client msgpack fixtures for new snapshot fields
- Fix debug.rs resource optionality (Option<ResMut> for
  ContaminationActive/EventQueue)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

server/tests/serialization.rs

@@ -38,6 +38,7 @@ fn test_snapshot(tick: u64, entities: Vec<VisibleEntity>) -> ObserverSnapshot {
         save_result: None,
         triangle_crisis_events: vec![],
         state_hash: None,
+        debug_response: None,
         sim_errors: vec![],
     }
 }
@@ -299,6 +300,7 @@ fn snapshot_v2_fields_roundtrip() {
         save_result: None,
         triangle_crisis_events: vec![],
         state_hash: None,
+        debug_response: None,
         sim_errors: vec![],
     };
 
@@ -354,7 +356,7 @@ fn protocol_version_constant_matches_snapshot() {
     let snapshot = test_snapshot(0, vec![]);
     assert_eq!(snapshot.version, PROTOCOL_VERSION);
     assert_eq!(
-        PROTOCOL_VERSION, 17,
+        PROTOCOL_VERSION, 18,
         "bump this assertion when protocol version changes"
     );
 }
@@ -406,6 +408,7 @@ fn all_facing_direction_variants_roundtrip() {
             save_result: None,
             triangle_crisis_events: vec![],
             state_hash: None,
+        debug_response: None,
             sim_errors: vec![],
         };
         let bytes = rmp_serde::to_vec_named(&snapshot).expect("serialize");