chore: migrate from runok to Bunosh, fix Lightpanda docs

[DavertMik]

Summary

• Bunoshfile.js is now the only task file. This PR deletes runok.cjs and removes the runok dependency. The docs, def and update-contributor-faces npm scripts now call bunosh.
• Fixes the Lightpanda docs. CI ran runok.cjs, whose inheritedHelperDocs list didn't include Lightpanda, so the page had no method list. The page is regenerated here: 139 → 1967 lines.
• Fixes three existing Bunoshfile bugs:
  • the MockRequest section in docs:external-helpers was missing
  • generated pages got an extra blank line after the front matter
  • helper/plugin file lists weren't sorted, which shuffled the docs/plugins.md index under Bun
• Removes the legacy release tasks (release, publishSite, wiki, versioning, get:commit-log, publish:next-beta-version) and the publish:site, prepare-release and publish-beta npm scripts. Releases go through GitHub Releases and publish-beta.yml, and the website refreshes itself by running its own bunosh docs.
• Adds oven-sh/setup-bun@v2 to doc-generation.yml, dtslint.yml and publish-beta.yml, because they run npm run def/docs. Pins bunosh to ^0.6.0 instead of latest.

Test plan

• npm run docs exits 0 and changes only docs/helpers/Lightpanda.md
• npm run def and npm run dtslint both exit 0
• eslint Bunoshfile.js passes
• CI Typings tests (dtslint) pass with bun set up

🤖 Generated with Claude Code