fix: gallery tag filters and tag-cleanup are empty in single-user mode (#1771)

routes/gallery_helpers.py

@@ -110,9 +110,17 @@ def _image_to_dict(img: GalleryImage, session_name: str = None) -> Dict[str, Any
 
 
 def _owner_filter(q, user):
-    """Apply owner filtering to a gallery query."""
+    """Apply owner filtering to a gallery query.
+
+    When auth is disabled (single-user mode) get_current_user returns None
+    and there is no per-user scoping. The main library list and stats already
+    treat None as "show everything" (`if user is not None`), so this helper
+    must too — otherwise the tag/model filter sidebars come back empty and the
+    tag-cleanup endpoints (clear-user-tags, clear-ai-tags, dedupe-tags)
+    silently affect zero rows in the most common self-hosted deployment.
+    """
     if user is None:
-        return q.filter(False)
+        return q
     return q.filter(GalleryImage.owner == user)