Remove blanket DEFAULTS backfill from DB get_sequence

Adding all DEFAULTS keys to API responses shifted output slot
indices, breaking existing ComfyUI workflow links (tuple index
out of range). Only lora migration remains on the DB read path.

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

db.py

@@ -5,7 +5,7 @@ import time
 from pathlib import Path
 from typing import Any
 
-from utils import load_json, DEFAULTS, KEY_BATCH_DATA, KEY_HISTORY_TREE
+from utils import load_json, KEY_BATCH_DATA, KEY_HISTORY_TREE
 
 logger = logging.getLogger(__name__)
 
@@ -232,8 +232,6 @@ class ProjectDB:
         if not row:
             return None
         data = json.loads(row["data"])
-        for k, v in DEFAULTS.items():
-            data.setdefault(k, v)
         return self._migrate_lora_keys(data)
 
     def list_sequences(self, data_file_id: int) -> list[int]: