feat(typecast): support optional silence duration

[hmmhmmhm]

Summary

• Expose params.output.remove_silence_ms in the Typecast manifest and preserve zero through the existing native SDK parameter path.
• Require typecast-python 0.3.15, which validates the optional integer 0–1000 contract. Omitted values preserve existing behavior; zero removes detected silence.
• Cover zero in config/request tests and one real basic-audio guarder configuration.

Validation

Using the prescribed ten_agent_build:0.7.14 image on linux/amd64:

• task check (Black 80): passed; generated .ten directory excluded only.
• task lint: 10.00/10.
• Standalone extension tests: 10 passed.
• Real Typecast vendor guarder: 15 passed, 2 skipped in 352.91 seconds. Websocket connection status and optional subtitle alignment are not enabled for this extension.
• git diff --check and staged secret scan: passed.
• Latest main change only affects Rime; Typecast source and harness are unchanged.

Publication dependency

Keep this draft until typecast-python 0.3.15 is published on PyPI and a registry-only installation is verified. The current tests used the built 0.3.15 wheel via the existing installer find-links option, not a public registry release. SDK feature: neosapience/typecast-sdk#160; release: neosapience/typecast-sdk#161.

No global defaults or runtime request routing changed.

[hmmhmmhm]

Validation update: the actual Typecast TTS guarder passed 15 tests (2 non-applicable skips) with the local typecast-python 0.3.15 release wheel. The claude-review job did not perform a review: run 35045313596 rejected actor hmmhmmhm because the fork author has read, not write, permission on upstream. A maintainer-authorized review/rerun is needed; no workflow permission changes are proposed. This PR remains draft until typecast-python 0.3.15 is available from PyPI and registry-only validation is complete.

[hmmhmmhm]

typecast-python 0.3.15 is now available on public PyPI. Re-ran the actual Typecast TTS guarder using the standard installation path with no local SDK wheel mount/override: 15 passed, 2 non-applicable skipped in 352.68s. The previous CI log explicitly failed because 0.3.15 was unpublished. Attempting to rerun run 35045313980 now returns "Must have admin rights to Repository". Please rerun that CI and provide/authorize the actual review; claude-review also rejected this fork author due to read-only upstream permissions. No permission bypass is proposed.