[FLINK-25802][FLINK-30499][table-planner] Fix TIMESTAMP codegen for RANGE OVER window bounds

[Izeren]

What is the purpose of the change

RangeBoundComparatorCodeGenerator produces Janino compile errors for RANGE OVER windows with TIMESTAMP ORDER BY columns. Two separate bugs:

1. (FLINK-25802) TIMESTAMP columns are bound as BigIntType but the raw TimestampData term is passed directly to ExprCodeGenerator.bindInput(), causing an invalid (Long) timestampData cast at runtime.

2. (FLINK-30499) TIMESTAMP_WITH_LOCAL_TIME_ZONE falls through the case _ default with no special handling, and ctx.reuseMemberCode() is emitted inside the compare() method body instead of at class scope, causing a Janino compile error for any type that triggers member code generation.

Both bugs surface as:

InvalidProgramException: Table program cannot be compiled. This is a bug.
  Caused by: CompileException: Cannot cast "org.apache.flink.table.data.TimestampData" to "java.lang.Long"

Brief change log

• Replace LogicalTypeRoot match with LogicalTypeFamily.TIMESTAMP / LogicalTypeFamily.TIME if/else to cover all three TIMESTAMP variants uniformly (and remain forward-compatible with future additions)
• Extract epoch milliseconds via .getMillisecond() before passing the value to ExprCodeGenerator.bindInput(), so the variable type matches the declared BigIntType
• Promote child CodeGeneratorContext member code to the parent context via addReusableMember(), placing class-level declarations at class scope rather than inside compare()
• Add regression tests in batch/sql/OverAggregateITCase for TIMESTAMP(3) and TIMESTAMP_LTZ(3) ORDER BY columns

Verifying this change

• Unit tests

Does this pull request potentially affect one of the following parts:

• Dependencies (does it add or upgrade a dependency): no
• The public API, i.e., is any changed class annotated with @Public(Evolving): no
• The serializers: no
• The runtime per-record code paths (performance sensitive): no (codegen path only; no per-record overhead)
• Anything that affects deployment or recovery: no
• The S3 file system connector: no

Documentation

• Does this pull request introduce a new feature? no

---

Was generative AI tooling used to co-author this PR?

• Yes (Claude Code)

[flinkbot]

CI report:

• d9de951 Azure: FAILURE
• 4933b95 Azure: PENDING

Bot commands

The @flinkbot bot supports the following commands:

• @flinkbot run azure re-run the last Azure build