添加 claude code game studios 到项目

.claude/rules/engine-code.md

@@ -0,0 +1,37 @@
+---
+paths:
+  - "src/core/**"
+---
+
+# Engine Code Rules
+
+- ZERO allocations in hot paths (update loops, rendering, physics) — pre-allocate, pool, reuse
+- All engine APIs must be thread-safe OR explicitly documented as single-thread-only
+- Profile before AND after every optimization — document the measured numbers
+- Engine code must NEVER depend on gameplay code (strict dependency direction: engine <- gameplay)
+- Every public API must have usage examples in its doc comment
+- Changes to public interfaces require a deprecation period and migration guide
+- Use RAII / deterministic cleanup for all resources
+- All engine systems must support graceful degradation
+- Before writing engine API code, consult `docs/engine-reference/` for the current engine version and verify APIs against the reference docs
+
+## Examples
+
+**Correct** (zero-alloc hot path):
+
+```gdscript
+# Pre-allocated array reused each frame
+var _nearby_cache: Array[Node3D] = []
+
+func _physics_process(delta: float) -> void:
+    _nearby_cache.clear()  # Reuse, don't reallocate
+    _spatial_grid.query_radius(position, radius, _nearby_cache)
+```
+
+**Incorrect** (allocating in hot path):
+
+```gdscript
+func _physics_process(delta: float) -> void:
+    var nearby: Array[Node3D] = []  # VIOLATION: allocates every frame
+    nearby = get_tree().get_nodes_in_group("enemies")  # VIOLATION: tree query every frame
+```