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/detection.py

@@ -28,8 +28,8 @@ def run_anomaly_window(conn, stable: str, algo: str) -> list[tuple[int, int]]:
 
     sql = (
         f"SELECT _WSTART, _WEND "
-        f"FROM (ANOMALY_WINDOW(value, \"algo={algo}\") "
-        f"FROM ds_{stable})"
+        f"FROM (SELECT ts, `value` AS v FROM ds_{stable}) "
+        f"ANOMALY_WINDOW(v, 'algo={algo}')"
     )
 
     rows = conn.execute(sql)