feat(mtmcanvas): extract Canvas as independent plugin

[codeh007]

Summary

• Extract the current Canvas Host/Client domain into the independent mtmcanvas package.
• Publish DSH Bundle and Web Client faces with dsh.bundle.patch, package checks, and the current Canvas contract/runtime tests.
• Remove Canvas code and Canvas-only peer dependencies from mtmharness; its standalone multi-user client remains untouched.

Related issue: codeh007/gomtm#664

Verification

• pnpm --filter mtmcanvas run check passed: 4 files, 12 tests, build, and package verification.
• pnpm --filter mtmharness run check passed: 22 Vitest files, 84 tests, 21 Node TAP tests, build, and package verification.
• A local mtmcanvas-0.1.0.tgz installed successfully into an isolated DSH Web profile.
• Running dsh --profile web --port 3194 exposed mtmcanvas in __DSH_BOOT__; /plugins/mtmcanvas/client.js returned the expected lazy-CJS loader artifact.

Release Blocker

npm whoami returned ENEEDAUTH in this environment, so mtmcanvas@0.1.0 has not been published to npm yet. The package is locally packed and verified; publish requires an npm-authenticated environment.

[coderabbitai]

Important

• 🔍 Trigger review

This repository does not receive automatic reviews because it has fewer than 10 stars.

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro Plus

Run ID: bad37756-b56c-44b2-b2d6-3baf0b3faa03

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands.}