fix(schema): escape TDengine 3.4 reserved words 'value'/'label' and use column alias for ANOMALY_WINDOW

- schema: rename label -> is_anomaly, escape `value` as backtick
- detection/forecast: wrap subquery with SELECT ts, `value` AS v
  so ANOMALY_WINDOW/FORECAST receive non-keyword column name
- resolves [0x2600] syntax error and unblocks E2E pipeline on community tsdb 3.4.1

ts_anomaly_td/schema.py

@@ -24,7 +24,7 @@ def create_supertable(conn, stable: str) -> None:
     """
     sql = (
         f"CREATE STABLE IF NOT EXISTS ds_{stable} "
-        f"(ts TIMESTAMP, value DOUBLE, label INT) "
+        f"(ts TIMESTAMP, `value` DOUBLE, is_anomaly INT) "
         f"TAGS (series_id INT)"
     )
     conn.execute_no_result(sql)