Fix library UDF edge cases

[Caideyipi]

Summary

• Fix validation, empty-input handling, and instance-reuse state leaks across library UDF/UDAF implementations.
• Fix timestamp alignment and invalid-value handling in batch profile/anomaly functions.
• Fix DWT multi-layer round-trip behavior and add focused regression coverage for UDF edge cases.

Tests

• mvn '-Ddevelocity.off=true' -pl library-udf spotless:apply
• mvn '-Ddevelocity.off=true' -pl library-udf '-Dtest=UDFWindowAndQueueTest' test
• mvn '-Ddevelocity.off=true' -pl library-udf test
• git diff --check -- library-udf