Route skipped modules into CI coverage

Engine changes skipped Kubernetes integration tests, ExampleUdfIT was not listed in any workflow job, and changes limited to seatunnel-trace or starter E2E paths triggered no Java test job at all.

Extends the engine job condition, includes the UDF module with additional timeout headroom, and adds a standalone path-to-module filter that routes trace-analyzer and starter-E2E changes into the existing unit-test workflow.

• Restores intended coverage for three classes of source changes that previously received no signal from their relevant tests.
• Adds structural regression tests that inspect the live workflow and module metadata, making future routing omissions detectable during ordinary CI.
• Reuses existing workflow conditions and module-selection conventions instead of introducing a parallel test-routing mechanism.
• The stronger coverage has a deliberate cost: engine changes add two Kubernetes legs, UDF routing adds build time, and trace-only or starter-only changes now trigger the full unit-test job.

• All 33 Python routing tests passed; new tests verify standalone mappings, real artifact identifiers, engine Kubernetes conditions, and coverage of non-connector E2E modules.
• ExampleUdfIT passed both tests on Java 8 and Java 11 using the same Maven invocation as CI.
• A local workflow simulation demonstrated the before-and-after job graph for trace, starter, engine, transform, connector, and documentation changes.
• All four hosted checks passed and two upstream contributors approved the authored change; the affected long-running jobs were not directly exercised by the fork workflow before merge.