[MichalCz]

Summary

Prepare the 0.9.3 patch release from merged main (c0f862d, including #85).

• Set all six workspace package versions and internal dependency pins to 0.9.3.
• Update package-lock.json and canonical Python pyproject.toml / uv.lock metadata to 0.9.3.
• Add the v0.9.3 changelog entry for request cancellation, receiving Guest cleanup signals, deterministic race/cross-runtime regression coverage, Bun CI provisioning, and removal of obsolete Conductor repository files.
• Keep the private root package at 0.0.0; no external dependency upgrades or production logic changes.

Validation

• npm test: build and staging passed; 594 tests passed, four intentional packaging-related skips, zero failures/cancellations.
• npm run test:package-consumers -- --source=staging: CJS, MJS, and TypeScript imports passed for all six packages.
• npm run test:package-consumers -- --source=tarball: CJS, MJS, and TypeScript imports passed for all six packages.
• npm run test:package-tarballs: 89/89 tests passed without skips.
• Read-only stable-tag policy check for 0.9.3: stable, latest, Python 0.9.3, next development version 0.9.4-next.0.
• Tracked-source Biome: 142 files passed. git diff --check passed.
• Local whole-root npm run lint: four formatting findings in untouched, unrelated, untracked .slim/worktrees/*/conductor/setup_state.json files. Those files are excluded from this PR; no ignore/config changes were made to hide the findings.

Release boundary

This PR prepares version metadata and the changelog only. No v0.9.3 tag, GitHub Release, or registry publication has been created. The policy checker describes the stable release channel; it does not authorize publishing.

Merge this PR manually through the protected main workflow. Any later release tag must target the merged release-preparation commit and requires separate explicit authorization.

Checklist

• Maintainer-authored preparation; versions and internal pins are aligned across JavaScript and Python.
• Generated artifacts, certificates, credentials, and unrelated worktree metadata are excluded.
• Release/tag/publishing remains maintainer-controlled.