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_crud.py

@@ -291,7 +291,18 @@ def sql_select(
         return [] if as_list else None
 
     # Fetch all rows first to determine actual count reliably
-    rows = result.all()
+    try:
+        # Check if the result set actually contains rows before fetching
+        if hasattr(result, 'returns_rows') and not result.returns_rows:
+            log.warning("SQL Result does not return rows (ResourceClosedError prevented).")
+            return [] if as_list else None
+            
+        rows = result.all()
+    except Exception as e:
+        log.error(f"SQL Fetch Error: {e}")
+        set_last_sql_error(e)
+        return [] if as_list else None
+
     count = len(rows)
 
     if count == 0: