Pipeline resilience: try/finally + startup recovery for stuck images

- process_image_pipeline: wrapped in try/finally to guarantee processing_status
  is always updated, even on unexpected crashes/timeouts
- init_db: recovery query that marks images stuck in 'processing' for >10min
  as ERROR on startup
- Clean rewrite of pipeline.py for consistent indentation

app/database.py

@@ -2,8 +2,10 @@
 Configuration SQLAlchemy — session async
 """
 import logging
+from datetime import datetime, timezone, timedelta
 from sqlalchemy.ext.asyncio import create_async_engine, AsyncSession, async_sessionmaker
 from sqlalchemy.orm import DeclarativeBase
+from sqlalchemy import select, text
 from app.config import settings
 
 logger = logging.getLogger(__name__)
@@ -44,9 +46,9 @@ async def get_db() -> AsyncSession:
 async def init_db():
     """Crée toutes les tables, applique les migrations, et initialise un client par défaut si nécessaire."""
     import secrets
-    from sqlalchemy import select, text
     from app.dependencies.auth import hash_api_key
     from app.models.client import APIClient, ClientPlan
+    from app.models.image import Image, ProcessingStatus
 
     async with engine.begin() as conn:
         from app.models import image  # noqa: F401
@@ -59,7 +61,7 @@ async def init_db():
                 "ALTER TABLE api_clients ADD COLUMN IF NOT EXISTS ai_provider VARCHAR(64)"
             ))
         except Exception:
-            pass  # SQLite ne supporte pas ADD COLUMN IF NOT EXISTS
+            pass
 
         try:
             await conn.execute(text(
@@ -68,8 +70,27 @@ async def init_db():
         except Exception:
             pass
 
-    # Vérifier s'il y a déjà des clients
+    # Vérifier s'il y a déjà des clients + recovery des images bloquées
     async with AsyncSessionLocal() as session:
+        # Recovery : marquer les images bloquées en "processing" depuis > 10 min comme ERROR
+        cutoff = datetime.now(timezone.utc) - timedelta(minutes=10)
+        stuck_query = select(Image).where(
+            Image.processing_status == ProcessingStatus.PROCESSING,
+            Image.processing_started_at < cutoff,
+        )
+        stuck_result = await session.execute(stuck_query)
+        stuck_images = stuck_result.scalars().all()
+        for img in stuck_images:
+            img.processing_status = ProcessingStatus.ERROR
+            img.processing_error = "[Recovery] Pipeline interrompu (timeout ou crash worker)"
+            img.processing_done_at = datetime.now(timezone.utc)
+        if stuck_images:
+            await session.commit()
+            logger.warning(
+                "init_db.recovery",
+                extra={"stuck_images_recovered": len(stuck_images)},
+            )
+
         result = await session.execute(select(APIClient).limit(1))
         if result.scalar_one_or_none() is None:
             # Table vide -> Création du client bootstrap