fix: handle byte[] complex types from realtime segments in MSQ scans (#18340)

[zhang-arvin]

Description

When MSQ scans realtime segments containing complex types, ColumnValueSelector.getObject() returns the already-serialized byte[] form rather than the deserialized object. ComplexMetricSerde.toBytes() calls ObjectStrategy.toBytes(val) which expects the deserialized object type T, causing a ClassCastException when the value is actually byte[].

This fix adds a new objectToBytes(Object val) default method to ObjectStrategy that checks if the value is already a byte[] and returns it directly, otherwise delegates to the existing toBytes(T val) method. ComplexMetricSerde.toBytes() is updated to use objectToBytes() instead of toBytes().

Changes

• ObjectStrategy.java: Added objectToBytes(Object val) default method that handles byte[] input directly
• ComplexMetricSerde.java: Changed toBytes(val) to objectToBytes(val) in the serde

Fixes #18340.

[FrankChen021]

I have reviewed the code for correctness, edge cases, concurrency, and integration risks; no issues found.

Reviewed 2 of 2 changed files.

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This is an automated review by Codex GPT-5.6-Luna(max)