fix(db): prevent silent failures in sql_select

- Modify sql_select to return False on database exceptions instead of an empty result
- Update V3 Search endpoint to catch False results and return a 500 Internal Server Error
- Enhances error visibility for frontend developers and prevents misleading 200 OK responses during SQL errors

app/lib_sql_crud.py

@@ -312,7 +312,7 @@ def sql_select(
     except Exception as e:
         log.error(f"SQL Fetch Error: {e}")
         set_last_sql_error(e)
-        return [] if as_list else None
+        return False
 
     count = len(rows)