docs(container): add auto-generated tool versions page

[matthew-on-git]

Summary

• Add /docs/container/versions/ page showing tool versions per dev-toolchain release
• Add .github/scripts/generate-versions-page.sh that fetches tool-versions.json from dev-toolchain release assets and generates a markdown page
• Add .github/workflows/update-tool-versions.yml — scheduled daily + manual dispatch, commits only when content changes
• Add cross-reference from container docs to the new page

How it works

1. dev-toolchain PR #4 adds tool-versions.json as a release asset
2. This workflow fetches those assets daily, renders them as sorted markdown tables
3. Latest release gets a full table; previous releases are in collapsible <details> blocks
4. Push to main triggers existing Cloudflare Pages deploy

No PAT needed — GITHUB_TOKEN can read the public dev-toolchain repo.

Test plan

• Ran generate script locally — fallback message shown correctly (no releases have the asset yet)
• Pre-commit and pre-push hooks pass
• CI build passes (Hugo build succeeds with new page)
• After dev-toolchain PR docs(standards): add Rust language ecosystem documentation #4 merges and a release is cut, manually trigger workflow to verify full output

🤖 Generated with Claude Code