fix(db): stabilize connection refreshing and prevent ResourceClosedError

- Update sql_connect to refresh global db object via reconnect_db
- Add returns_rows check and safe fetch block in sql_select
- Prevents 500 errors during transient database connection issues

app/lib_sql_core.py

@@ -77,10 +77,12 @@ def reconnect_db() -> bool:
         log.exception("DB SQL Core: FAILED to refresh database connection!")
         return False
 
-def sql_connect(current_db, log_lvl: int = logging.INFO) -> bool:
-    """Old compatibility wrapper for disposing the engine."""
-    if current_db:
-        current_db.engine.dispose()
-        log.info('DB SQL Core: Disposed of the current engine via sql_connect.')
-        return True
-    return False
+def sql_connect(current_db=None, log_lvl: int = logging.INFO) -> bool:
+
+    """Refreshes the global database connection."""
+
+    log.setLevel(log_lvl)
+
+    log.info('DB SQL Core: Refreshing database connection via sql_connect...')
+
+    return reconnect_db()