Flink

JdbcSinkFunction.invoke() SQL Injection via Unvalidated Identifiers

The `JdbcSinkFunction.invoke()` method in Lacus's RTC engine built SQL INSERT statements with `String.format()`, placing database name, table name, and column names directly into the query string without validation. Although the actual row values used parameterized `?` placeholders, the identifiers themselves were injectable, letting a crafted sink configuration break out of the intended INSERT statement. The fix adds a strict allowlist regex that rejects any identifier containing characters out