fix: use connection context instead of LazyEngine directly for read_sql/to_sql

src/similarity_model/sync_projects.py

@@ -44,12 +44,14 @@ def sync_projects():
     )
     """
     logger.info("Fetching raw active projects from 'Projects' table...")
-    projects_df = pd.read_sql(projects_query, engine)
+    with engine.connect() as conn:
+        projects_df = pd.read_sql(projects_query, conn)
     logger.info(f"Loaded {len(projects_df)} active projects from database.")
 
     # 2. Fetch existing preprocessed projects
     logger.info("Fetching existing records from 'PreProcessed_Projects'...")
-    existing_df = pd.read_sql("SELECT id FROM PreProcessed_Projects", engine)
+    with engine.connect() as conn:
+        existing_df = pd.read_sql("SELECT id FROM PreProcessed_Projects", conn)
     
     allowed_ids = set(projects_df["Id"].tolist())
     processed_ids = set(existing_df["id"].tolist())
@@ -118,12 +120,13 @@ def sync_projects():
 
             # Insert into database
             logger.info("Uploading preprocessed records to database...")
-            processed_df.to_sql(
-                "PreProcessed_Projects",
-                engine,
-                if_exists="append",
-                index=False
-            )
+            with engine.begin() as conn:
+                processed_df.to_sql(
+                    "PreProcessed_Projects",
+                    conn,
+                    if_exists="append",
+                    index=False
+                )
             logger.info(f"Successfully processed and inserted {len(processed_df)} projects.")
             changed = True
         else: