feat: route all html editor API mutations through single owner task

1 files changed, 4 insertions, 0 deletions

diff --git a/internal/admin/undo.go b/internal/admin/undo.go
index 0f9744c..98d8d9a 100644
--- a/internal/admin/undo.go
+++ b/internal/admin/undo.go
@@ -61,6 +61,10 @@ type UndoInfo struct {
 	RedoSize  int    `json:"redo_size"`
 }
 
+// UndoStack protects history with a mutex, not live game state. Production
+// callers must execute Push/Undo/Redo/Clear within the editor's owner task.
+// Undo/Redo and the subsequent rebuildAfterUndo are one task, not separate
+// dispatches; migrateRoomIDs is an owner-only callback.
 type UndoStack struct {
 	mu       sync.Mutex
 	dataDir  string