feat(simulation): add Zone Gate gauntlet room and zone crossing detection (#512)

New test_world room with two zones (Terminal/Corridor) separated by
a door. Adds ZoneCrossEventQueue resource and detect_zone_crossings
system to fire events when the player crosses zone boundaries.

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

server/src/test_world/mod.rs

@@ -16,7 +16,7 @@
 //!   - Entities spawned in canonical order → StableId assignment is deterministic
 //!   - Additive-only: existing rooms/entities never reordered
 //!
-//! StableId ranges (from gestalt-round3.md + Sprint 11 + Sprint 13):
+//! StableId ranges (from gestalt-round3.md + Sprint 11 + Sprint 13 + Sprint 22):
 //!   Player: 0
 //!   Hub signs: 1-4
 //!   Fog Theater: 5-8
@@ -35,6 +35,8 @@
 //!   Decay Observatory: 69
 //!   Shift Change: 70-71
 //!   Reset plates (Sprint 13 rooms): 72-74
+//!   Zone Gate: 75 (door entity)
+//!   Reset plates (Sprint 22 rooms): 76
 
 #[cfg(feature = "gauntlet")]
 pub mod constants;
@@ -113,6 +115,8 @@ pub fn setup_gauntlet(app: &mut App) {
     carve_room_interior(&mut walkability, 0, 104, 34, 20); // Sound Lab
     carve_room_interior(&mut walkability, 0, 24, 24, 14); // Decay Observatory
     carve_room_interior(&mut walkability, 64, 78, 16, 24); // Shift Change
+    // Sprint 22 rooms
+    carve_room_interior(&mut walkability, 64, 102, 16, 22); // Zone Gate
 
     // Carve corridors between hub and rooms
     carve_corridor(&mut walkability, 48, 34, 6, 12); // corridor-N: Hub ↔ Fog Theater
@@ -144,8 +148,13 @@ pub fn setup_gauntlet(app: &mut App) {
 
     // Zone map: assign zone IDs per room bounding box (D-077, D-073).
     // Zone IDs are sequential per ROOMS order. Corridors remain unzoned (None).
+    // Exception: Zone Gate (index 14) uses two explicit zone IDs for its dual-zone split.
     let mut zone_map = ZoneMap::default();
     for (i, room) in constants::ROOMS.iter().enumerate() {
+        // Zone Gate handled separately below — skip in the sequential loop.
+        if room.name == "zone_gate" {
+            continue;
+        }
         let zone_id = i as u16;
         zone_map.set_rect(
             room.origin.x,
@@ -156,6 +165,23 @@ pub fn setup_gauntlet(app: &mut App) {
             zone_id,
         );
     }
+    // Zone Gate: Terminal side (left 8 cols, x=64-71) and Corridor side (right 8 cols, x=72-79).
+    zone_map.set_rect(
+        constants::ZONE_GATE.origin.x,
+        constants::ZONE_GATE.origin.y,
+        constants::ZONE_GATE.size.0 / 2,
+        constants::ZONE_GATE.size.1,
+        constants::ZONE_GATE.origin.z,
+        constants::ZONE_GATE_TERMINAL_ZONE_ID,
+    );
+    zone_map.set_rect(
+        constants::ZONE_GATE.origin.x + constants::ZONE_GATE.size.0 / 2,
+        constants::ZONE_GATE.origin.y,
+        constants::ZONE_GATE.size.0 / 2,
+        constants::ZONE_GATE.size.1,
+        constants::ZONE_GATE.origin.z,
+        constants::ZONE_GATE_CORRIDOR_ZONE_ID,
+    );
     app.insert_resource(zone_map);
 
     // Entity spawning in canonical StableId order.
@@ -333,6 +359,9 @@ pub fn setup_gauntlet(app: &mut App) {
     }
 
     // --- Sprint 13 reset plates (StableId 72-74) ---
+    // NOTE: Sprint 22 reset plate (zone_gate) is spawned AFTER these to maintain additive order.
+    // The sprint13 block is numbered 72-74; zone_gate entities are 75; sprint22 plate is 76.
+    // The spawn order below matches the StableId allocation table in the module doc.
     let sprint13_reset_plates: &[(&str, TilePosition)] = &[
         (
             "sound_lab",
@@ -370,6 +399,34 @@ pub fn setup_gauntlet(app: &mut App) {
             .insert(StableEntityId(sid));
     }
 
+    // --- Zone Gate (StableId 75) ---
+    // Spawned AFTER Sprint 13 reset plates so it gets ID 75 per the allocation table.
+    rooms::zone_gate::spawn_entities(app, &mut registry);
+
+    // --- Sprint 22 reset plates (StableId 76) ---
+    let sprint22_reset_plates: &[(&str, TilePosition)] = &[(
+        "zone_gate",
+        constants::ZONE_GATE
+            .reset_plate
+            .expect("zone_gate should have a reset_plate"),
+    )];
+    for &(room_name, pos) in sprint22_reset_plates {
+        let entity = app
+            .world_mut()
+            .spawn((
+                Interactable,
+                RoomResetTrigger {
+                    room_name: room_name.to_string(),
+                },
+                pos,
+            ))
+            .id();
+        let sid = registry.register(entity);
+        app.world_mut()
+            .entity_mut(entity)
+            .insert(StableEntityId(sid));
+    }
+
     // --- Populate RoomSnapshots for reset mechanism (#490) ---
     let mut snapshots = RoomSnapshots::default();
 
@@ -495,6 +552,15 @@ pub fn setup_gauntlet(app: &mut App) {
         }
     }
 
+    // Zone Gate entities (StableId 75): door only, no floor items
+    for id in constants::ZONE_GATE_STABLE_IDS.0..=constants::ZONE_GATE_STABLE_IDS.1 {
+        if let Some(entity) = registry.to_entity(&StableId(id)) {
+            if let Some(pos) = app.world().get::<TilePosition>(entity) {
+                snapshots.record("zone_gate", entity, *pos, false);
+            }
+        }
+    }
+
     app.insert_resource(snapshots);
 
     // --- Sprint 14 component fixup ---
@@ -864,5 +930,25 @@ mod tests {
                 id
             );
         }
+
+        // Zone Gate at 75
+        for id in constants::ZONE_GATE_STABLE_IDS.0..=constants::ZONE_GATE_STABLE_IDS.1 {
+            assert!(
+                registry.to_entity(&StableId(id)).is_some(),
+                "Zone Gate at StableId {}",
+                id
+            );
+        }
+
+        // Sprint 22 reset plate at 76
+        for id in constants::SPRINT22_RESET_PLATE_STABLE_IDS.0
+            ..=constants::SPRINT22_RESET_PLATE_STABLE_IDS.1
+        {
+            assert!(
+                registry.to_entity(&StableId(id)).is_some(),
+                "Sprint 22 reset plate at StableId {}",
+                id
+            );
+        }
     }
 }