Fix factory reset and improve reset_stage CI job

- Add create_default_admin() call to factory reset (admin user wasn't being
  created after reset, only on server restart)
- Add retry logic to reset_stage CI job (3 attempts with 5s delay)
- Use proper context manager for httpx client
- Increase timeout to 120s for reset operation
- Add retry: 1 at job level for transient failures

backend/app/routes.py

@@ -6481,8 +6481,12 @@ def factory_reset(
         # Step 4: Re-seed with default data (need fresh session after schema recreate)
         logger.info("Seeding database with defaults...")
         from .seed import seed_database
+        from .auth import create_default_admin
         fresh_db = SessionLocal()
         try:
+            # Create default admin user first (normally done at startup)
+            create_default_admin(fresh_db)
+            # Then seed other test data
             seed_database(fresh_db)
             fresh_db.commit()
         finally: