fix(images): a monitor invalidation rebuilds only the new files' values

The image monitor invalidates the gallery whenever it sees a new file,
and that dropped every derived workspace value, so the next request paid
a full cold build. Invalidation now keeps the per-file values and drops
only the sort orders; the rescan reuses every unchanged file and builds
only new or changed ones. A gallery-roots change still drops everything.

py/api/__init__.py

@@ -353,12 +353,18 @@ class PromptManagerAPI(
         """Invalidate the cached gallery file listing.
 
         Called by the image monitor when new files are detected. The workspace
-        values derived from a scan are dropped with it.
+        keeps its per-file values, so the next request rebuilds only new or
+        changed files (see ImageRoutesMixin._workspace_listed); its sort orders
+        are dropped, as the rescan replaces them anyway.
         """
         self._gallery_cache = {}
-        self._workspace_listed_cache = {}
         self._workspace_order_cache = {}
 
+    def reset_gallery_roots_cache(self):
+        """Drop every cached listing and derived workspace value (roots changed)."""
+        self.invalidate_gallery_cache()
+        self._workspace_listed_cache = {}
+
     def add_routes(self, routes):
         """Register all API routes with the ComfyUI server.
 

py/api/admin.py

@@ -897,7 +897,7 @@ class AdminRoutesMixin:
             return False
         GalleryConfig.MONITORING_DIRECTORIES = roots
         self._cached_output_dir = None
-        self.invalidate_gallery_cache()
+        self.reset_gallery_roots_cache()
         return True
 
     def _persist_settings(self):

py/api/images.py

@@ -990,7 +990,7 @@ class ImageRoutesMixin:
         The gallery cache hands out the same list object until it rescans.
         A rescan reuses the value of every unchanged ``(path, mtime)`` and,
         when nothing changed, the previous list itself, so the cached sort
-        orders stay valid. invalidate_gallery_cache drops these values.
+        orders stay valid. Only a gallery-roots change drops these values.
         """
         key = (index, str(root))
         cached = self._workspace_listed_cache.get(key)

tests/test_api_workspace_images.py

@@ -1200,14 +1200,18 @@ class TestWorkspaceImages(ImageAPITestCase):
             self.assertEqual(built, [added[0]])
             self.assertEqual(data["total"], len(listed))
             self.assertEqual(data["images"][0]["filename"], "new.png")
-            # Invalidation (the monitor saw new files) and a roots change drop
-            # every derived value.
+            # The monitor invalidates the gallery when it sees a new file: the
+            # next request rebuilds only that file's values, and search finds it.
             self.api.invalidate_gallery_cache()
-            self.assertEqual(self.api._workspace_listed_cache, {})
-            self.assertEqual(self.api._workspace_order_cache, {})
+            self.assertNotEqual(self.api._workspace_listed_cache, {})
+            monitored = (self.output_dir / "day-01" / "monitored.png", 9_999_999.5)
+            scans.append([monitored, *scans[-1]])
             built.clear()
-            response, data = await self.get(limit=10)
-            self.assertEqual(len(built), len(listed))
+            response, data = await self.get(limit=10, q="monitored")
+            self.assertEqual(response.status, 200)
+            self.assertEqual(built, [monitored[0]])
+            self.assertEqual(self._names(data), ["monitored.png"])
+            # A roots change drops every derived value.
             with patch("py.config.GalleryConfig.MONITORING_DIRECTORIES", []):
                 self.assertTrue(self.api._apply_gallery_roots([str(self.output_dir)]))
             self.assertEqual(self.api._workspace_listed_cache, {})