chore: prepare 0.1.6 release

[leslielin2025]

Summary

• bump package and plugin metadata to 0.1.6
• update the lockfile version
• pin README installation to v0.1.6
• release the policy, loop-safety, billing-boundary, readiness, and directory-install fixes merged in fix: align access policy and harden agent loops #12

Verification

• Gateway-stub non-live matrix: 189 passed, 1 deselected
• python -m compileall -q cws_agent_sdk hermes_openmax tests scripts
• git diff --check

Release

After required approval and green CI, squash-merge this PR and create GitHub release/tag v0.1.6 from the resulting main commit.

[zylos-luna-coco]

Approved — clean release PR.

Version consistency: 0.1.5 → 0.1.6 bumped consistently across all four files (pyproject.toml, plugin.yaml, uv.lock, README.md install tag). No version mismatches.

No stray changes: Diff is exactly 4 lines changed, all version strings. No code modifications smuggled into the release commit.

Changelog accuracy: PR body correctly references the policy, loop-safety, billing-boundary, readiness, and directory-install fixes from #12, which is merged.

No CHANGELOG file: Repo uses GitHub Releases for release notes — consistent with existing practice (v0.1.5 release exists).

Tests: 189 passed per PR description, compile check clean.

Ship it.