fix(ocr): fix event loop initialization in celery and update gemini model versions

src/config.py

@@ -102,8 +102,8 @@ class Settings(BaseSettings):
 
     # ── AI / LLM ─────────────────────────────────────────────────────────────
     GEMINI_API_KEY: SecretStr = Field(..., description="Google Gemini API key")
-    GEMINI_MODEL_PRIMARY: str = "gemini-3.1-pro"
-    GEMINI_MODEL_FALLBACK: str = "gemini-3.5-flash"
+    GEMINI_MODEL_PRIMARY: str = "gemini-1.5-pro"
+    GEMINI_MODEL_FALLBACK: str = "gemini-1.5-flash"
     OPENAI_API_KEY: SecretStr = ""  # type: ignore[assignment]
     EMBEDDING_MODEL: str = "text-embedding-3-small"
 

src/tasks/celery_app.py

@@ -42,12 +42,22 @@ from ..config import settings
 from celery.signals import worker_process_init
 import asyncio
 
+_worker_loop = None
+
 @worker_process_init.connect
 def init_celery_worker(**kwargs):
+    global _worker_loop
     from ..dependencies import init_supabase
-    loop = asyncio.new_event_loop()
-    asyncio.set_event_loop(loop)
-    loop.run_until_complete(init_supabase())
+    _worker_loop = asyncio.new_event_loop()
+    asyncio.set_event_loop(_worker_loop)
+    _worker_loop.run_until_complete(init_supabase())
+
+def get_worker_loop():
+    global _worker_loop
+    if _worker_loop is None:
+        _worker_loop = asyncio.new_event_loop()
+        asyncio.set_event_loop(_worker_loop)
+    return _worker_loop
 
 # ── Celery app ────────────────────────────────────────────────────────────────
 celery_app = Celery(

src/tasks/ocr_tasks.py

@@ -120,7 +120,8 @@ def preprocess_document(self, batch_id: str) -> None:
     from ..ai.graph import extraction_graph
     log.info("Starting extraction pipeline", batch_id=batch_id)
     try:
-        loop = asyncio.get_event_loop()
+        from .celery_app import get_worker_loop
+        loop = get_worker_loop()
         config = {"configurable": {"thread_id": batch_id}}
         context = loop.run_until_complete(_load_batch_context(batch_id))
         initial_state = {