feat(kernel): forward identity federation client ID

[vuanhphung]

Threads identity_federation_client_id from connect() through the kernel auth bridge to the PyO3 Session for PAT, OAuth M2M, and OAuth U2M. This enables SP-wide workload identity federation added in databricks-sql-kernel#248.

Pins KERNEL_REV to the merged kernel commit so kernel E2E builds against the matching API, and updates the public documentation. The published 0.2.0 wheel does not include this API; the dependency floor should be updated after the next kernel wheel release.

Validation: syntax check, whitespace check, and repository commit hooks passed. Unit tests were not run because Poetry is unavailable in the local checkout.

[peco-review-bot]

Verdict: 1 Medium

Looks good — the federation client ID is threaded correctly through all three kernel auth paths (M2M/PAT/U2M) with guards consistent with the updated docstrings and the session.py plumbing. One medium concern: the new forwarding behavior has no unit-test coverage in the otherwise-thorough bridge test suite.

[peco-review-bot]

Verdict: 1 Medium

Looks good overall — the identity_federation_client_id threading through the kernel auth bridge, session, and docs is consistent and correct across all three auth paths. One medium concern: the new forwarding behavior has no unit-test coverage despite the existing bridge test suite pinning every other forwarded kwarg.

[peco-review-bot]

✅ No issues identified by the review bot.