fix: use await engine.connect() instead of async with

SQLAlchemy 2.0 async engine.connect() doesn't support context manager.
Use explicit connect/close instead.

apps/api/src/database.py

@@ -44,8 +44,11 @@ async def init_database(
         try:
             # Test basic connectivity
             from sqlalchemy import text
-            async with engine.connect() as conn:
+            conn = await engine.connect()
+            try:
                 await conn.execute(text("SELECT 1"))
+            finally:
+                await conn.close()
 
             logger.info("Database connection established.")