perf(recipe_scanner): eliminate event loop blocking during cache rebuild

Refactor force_refresh path to use thread pool execution instead of blocking
the event loop shared with ComfyUI. Key changes:

- Fix 1: Route force_refresh through _initialize_recipe_cache_sync() in thread pool
- Fix 2: Add GIL release points (time.sleep(0)) every 100 files in sync loops
- Fix 3: Move RecipeCache.resort() to thread pool via run_in_executor
- Fix 4: Persist cache automatically after force_refresh
- Fix 5: Increase yield frequency in _enrich_cache_metadata (every recipe)

This eliminates the ~5 minute freeze when rebuilding 30K recipe cache.

Fixes performance issue where ComfyUI became unresponsive during recipe
scanning due to shared Python event loop blocking.

py/services/recipe_cache.py

@@ -4,6 +4,7 @@ from dataclasses import dataclass
 from operator import itemgetter
 from natsort import natsorted
 
+
 @dataclass
 class RecipeCache:
     """Cache structure for Recipe data"""
@@ -21,11 +22,18 @@ class RecipeCache:
         self.folder_tree = self.folder_tree or {}
 
     async def resort(self, name_only: bool = False):
-        """Resort all cached data views"""
+        """Resort all cached data views in a thread pool to avoid blocking the event loop."""
         async with self._lock:
-            self._resort_locked(name_only=name_only)
+            loop = asyncio.get_event_loop()
+            await loop.run_in_executor(
+                None,
+                self._resort_locked,
+                name_only,
+            )
 
-    async def update_recipe_metadata(self, recipe_id: str, metadata: Dict, *, resort: bool = True) -> bool:
+    async def update_recipe_metadata(
+        self, recipe_id: str, metadata: Dict, *, resort: bool = True
+    ) -> bool:
         """Update metadata for a specific recipe in all cached data
 
         Args:
@@ -37,7 +45,7 @@ class RecipeCache:
         """
         async with self._lock:
             for item in self.raw_data:
-                if str(item.get('id')) == str(recipe_id):
+                if str(item.get("id")) == str(recipe_id):
                     item.update(metadata)
                     if resort:
                         self._resort_locked()
@@ -52,7 +60,9 @@ class RecipeCache:
             if resort:
                 self._resort_locked()
 
-    async def remove_recipe(self, recipe_id: str, *, resort: bool = False) -> Optional[Dict]:
+    async def remove_recipe(
+        self, recipe_id: str, *, resort: bool = False
+    ) -> Optional[Dict]:
         """Remove a recipe from the cache by ID.
 
         Args:
@@ -64,14 +74,16 @@ class RecipeCache:
 
         async with self._lock:
             for index, recipe in enumerate(self.raw_data):
-                if str(recipe.get('id')) == str(recipe_id):
+                if str(recipe.get("id")) == str(recipe_id):
                     removed = self.raw_data.pop(index)
                     if resort:
                         self._resort_locked()
                     return removed
         return None
 
-    async def bulk_remove(self, recipe_ids: Iterable[str], *, resort: bool = False) -> List[Dict]:
+    async def bulk_remove(
+        self, recipe_ids: Iterable[str], *, resort: bool = False
+    ) -> List[Dict]:
         """Remove multiple recipes from the cache."""
 
         id_set = {str(recipe_id) for recipe_id in recipe_ids}
@@ -79,21 +91,25 @@ class RecipeCache:
             return []
 
         async with self._lock:
-            removed = [item for item in self.raw_data if str(item.get('id')) in id_set]
+            removed = [item for item in self.raw_data if str(item.get("id")) in id_set]
             if not removed:
                 return []
 
-            self.raw_data = [item for item in self.raw_data if str(item.get('id')) not in id_set]
+            self.raw_data = [
+                item for item in self.raw_data if str(item.get("id")) not in id_set
+            ]
             if resort:
                 self._resort_locked()
             return removed
 
-    async def replace_recipe(self, recipe_id: str, new_data: Dict, *, resort: bool = False) -> bool:
+    async def replace_recipe(
+        self, recipe_id: str, new_data: Dict, *, resort: bool = False
+    ) -> bool:
         """Replace cached data for a recipe."""
 
         async with self._lock:
             for index, recipe in enumerate(self.raw_data):
-                if str(recipe.get('id')) == str(recipe_id):
+                if str(recipe.get("id")) == str(recipe_id):
                     self.raw_data[index] = new_data
                     if resort:
                         self._resort_locked()
@@ -105,7 +121,7 @@ class RecipeCache:
 
         async with self._lock:
             for recipe in self.raw_data:
-                if str(recipe.get('id')) == str(recipe_id):
+                if str(recipe.get("id")) == str(recipe_id):
                     return dict(recipe)
         return None
 
@@ -115,16 +131,13 @@ class RecipeCache:
         async with self._lock:
             return [dict(item) for item in self.raw_data]
 
-    def _resort_locked(self, *, name_only: bool = False) -> None:
+    def _resort_locked(self, name_only: bool = False) -> None:
         """Sort cached views. Caller must hold ``_lock``."""
 
         self.sorted_by_name = natsorted(
-            self.raw_data,
-            key=lambda x: x.get('title', '').lower()
+            self.raw_data, key=lambda x: x.get("title", "").lower()
         )
         if not name_only:
             self.sorted_by_date = sorted(
-                self.raw_data,
-                key=itemgetter('created_date', 'file_path'),
-                reverse=True
-            )
+                self.raw_data, key=itemgetter("created_date", "file_path"), reverse=True
+            )