codemap generation

docs/CODE_OF_CONDUCT.md

@@ -208,6 +208,89 @@ func load_scene(path: String) -> void:
     get_tree().change_scene_to_packed(packed_scene)
 ```
 
+### Memory Management Standards
+
+**Critical Rules**:
+1. **Always use `queue_free()`** instead of `free()` for node cleanup
+2. **Wait for frame completion** after queueing nodes for removal
+3. **Clear references before cleanup** to prevent access to freed memory
+4. **Connect signals properly** for dynamically created nodes
+
+```gdscript
+# ✅ Correct memory management
+for child in children_to_remove:
+    child.queue_free()
+await get_tree().process_frame  # Wait for cleanup
+
+# ❌ Dangerous pattern (causes crashes)
+for child in children_to_remove:
+    child.free()  # Immediate deletion can crash
+```
+
+**Why This Matters**: Using `free()` causes immediate deletion which can crash if the node is still referenced elsewhere. `queue_free()` waits until it's safe to delete.
+
+**See Also**: [ARCHITECTURE.md](ARCHITECTURE.md#memory-management-queue_free-over-free) for architectural rationale.
+
+### Input Validation Standards
+
+All user inputs must be validated before processing.
+
+**Validation Requirements**:
+1. **Type checking**: Verify input types before processing
+2. **Bounds checking**: Validate numeric ranges and array indices
+3. **Null checking**: Handle null and empty inputs gracefully
+4. **Whitelist validation**: Validate against known good values
+
+```gdscript
+# ✅ Proper input validation
+func set_volume(value: float, setting_key: String) -> bool:
+    # Whitelist validation
+    if not setting_key in ["master_volume", "music_volume", "sfx_volume"]:
+        DebugManager.log_error("Invalid volume setting key: " + str(setting_key), "Settings")
+        return false
+
+    # Bounds checking
+    var clamped_value = clamp(value, 0.0, 1.0)
+    if clamped_value != value:
+        DebugManager.log_warn("Volume value clamped from %f to %f" % [value, clamped_value], "Settings")
+
+    SettingsManager.set_setting(setting_key, clamped_value)
+    return true
+
+# ✅ Grid movement validation
+func _move_cursor(direction: Vector2i) -> void:
+    # Bounds checking
+    if abs(direction.x) > 1 or abs(direction.y) > 1:
+        DebugManager.log_error("Invalid cursor direction: " + str(direction), "Match3")
+        return
+
+    # Null/empty checking
+    if not grid or grid.is_empty():
+        DebugManager.log_error("Grid not initialized", "Match3")
+        return
+
+    # Process validated input
+    var new_pos = cursor_pos + direction
+    # ... continue with validated data
+```
+
+**See Also**: [ARCHITECTURE.md](ARCHITECTURE.md#input-validation-whitelist-approach) for architectural decision rationale.
+
+## Code Quality Checklist
+
+Before committing code, verify:
+
+- [ ] All user inputs validated (type, bounds, null checks)
+- [ ] Error handling with fallback mechanisms implemented
+- [ ] Memory cleanup uses `queue_free()` not `free()`
+- [ ] No global static state introduced
+- [ ] Proper logging with categories and appropriate levels
+- [ ] Race condition protection for async operations
+- [ ] Input actions defined in project input map
+- [ ] Resources loaded with null/type checking
+- [ ] Documentation updated for new public APIs
+- [ ] Test coverage for new functionality
+
 ## Git Workflow
 
 ### Commit Guidelines