Add semantic tagging, search, favourite/NSFW filtering, and LLM job queue

Replaces old list-format tags (which duplicated prompt content) with structured
dict tags per category (origin_series, outfit_type, participants, style_type,
scene_type, etc.). Tags are now purely organizational metadata — removed from
the prompt pipeline entirely.

Adds is_favourite and is_nsfw columns to all 8 resource models. Favourite is
DB-only (user preference); NSFW is mirrored in JSON tags for rescan persistence.
All library pages get filter controls and favourites-first sorting.

Introduces a parallel LLM job queue (_enqueue_task + _llm_queue_worker) for
background tag regeneration, with the same status polling UI as ComfyUI jobs.
Fixes call_llm() to use has_request_context() fallback for background threads.

Adds global search (/search) across resources and gallery images, with navbar
search bar. Adds gallery image sidecar JSON for per-image favourite/NSFW metadata.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

app.py

@@ -119,6 +119,20 @@ if __name__ == '__main__':
                 else:
                     print(f"Migration settings note ({col_name}): {e}")
 
+        # Migration: Add is_favourite and is_nsfw columns to all resource tables
+        _tag_tables = ['character', 'look', 'outfit', 'action', 'style', 'scene', 'detailer', 'checkpoint']
+        for _tbl in _tag_tables:
+            for _col, _type in [('is_favourite', 'BOOLEAN DEFAULT 0'), ('is_nsfw', 'BOOLEAN DEFAULT 0')]:
+                try:
+                    db.session.execute(text(f'ALTER TABLE {_tbl} ADD COLUMN {_col} {_type}'))
+                    db.session.commit()
+                    print(f"Added {_col} column to {_tbl} table")
+                except Exception as e:
+                    if 'duplicate column name' in str(e).lower() or 'already exists' in str(e).lower():
+                        pass
+                    else:
+                        print(f"Migration note ({_tbl}.{_col}): {e}")
+
         # Ensure settings exist
         if not Settings.query.first():
             db.session.add(Settings())