chore(release): bump kimi-cli to 1.49.0 and kosong to 0.55.0

[sailist]

Summary

• Bump kimi-cli to 1.49.0
• Bump kosong to 0.55.0
• Move the current release notes under 1.49.0 / 0.55.0, and the breaking-change entry under 1.49.0 (en + zh)
• Update the root kosong[contrib] pin to 0.55.0 and sync the kimi-code wrapper to 1.49.0

Validation

• uv run python scripts/check_version_tag.py --pyproject pyproject.toml --expected-version 1.49.0
• uv run python scripts/check_version_tag.py --pyproject packages/kimi-code/pyproject.toml --expected-version 1.49.0
• uv run python scripts/check_version_tag.py --pyproject packages/kosong/pyproject.toml --expected-version 0.55.0
• uv run python scripts/check_kimi_dependency_versions.py --root-pyproject pyproject.toml --kosong-pyproject packages/kosong/pyproject.toml --pykaos-pyproject packages/kaos/pyproject.toml
• make check

Post-merge

After this PR lands, create and push the release tags:

git tag 1.49.0
git tag kosong-0.55.0
git push origin 1.49.0 kosong-0.55.0

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[devin-ai-integration]

✅ Devin Review: No Issues Found

Devin Review analyzed this PR and found no bugs or issues to report.