M3 Expressive components and a 3.0 docs site built on labs/gb

[MahmoodKhalil57]

Hi! I've been extending labs/gb toward the full Material 3 Expressive spec, and I'd like to contribute the useful parts in a way that fits your review process.

• Live demo: https://mahmoodkhalil57.github.io/material-web/3.0/
• Code: the m3-spec-pipeline branch of my fork, https://github.com/MahmoodKhalil57/material-web/tree/m3-spec-pipeline

What the branch has

• A spec pipeline in scripts/m3. It downloads the M3 spec locally without committing it and splits it into about 15,000 checkable units. Each unit is tested, excluded with a written reason, or listed as a known gap. The pipeline also generates the component token files and spec conformance tests, and it compares the tokens against the M3 token database.
• The existing labs/gb components, updated against that checklist. They have central axe and WAI-ARIA 1.3 test suites, Baseline checks and size budgets. Newer CSS is wrapped in @supports, or a comment says why it doesn't need to be.
• 16 new components in the same style. These are carousel, date picker, dialog, FAB menu, loading indicator, navigation drawer, progress, pull to refresh, scaffold, search, segmented button, select, sheets, text field, time picker and tooltip. The loading indicator's shape morphing is ported from Compose.
• A 3.0 docs site in the catalog at /3.0/. It's built with labs/gb and has live demos, search and a navigation rail with M3 motion. Each component page has a Compatibility section with M3 spec coverage, Baseline status, WAI-ARIA roles and Lighthouse scores for the component on its own test page.

This is too big to merge as it is, and CONTRIBUTING.md says new components need your internal reviews. So I'm starting with three small fixes to existing components, each in its own PR:

• fix(labs): nav rail menu button doesn't stay pressed while expanded #6111 The nav rail's menu button stays pressed while the rail is expanded.
• fix(labs): split button clicks on the menu icon and touch targets #6112 The split button's touch target covers the page around it, and its chevron doesn't respond to clicks.
• fix(labs): link buttons don't underline their label #6113 Link buttons (href) underline their label.

Questions

1. Which parts would help you, if any? I'm thinking of the per-component fixes, the new components as reference implementations, the test suites, and the token and test generators.
2. For component changes, do you want one PR per component or one PR per kind of fix?
3. Is there a roadmap for labs/gb I should follow, so I don't duplicate work in progress? I've seen the recent effects state and --disabled changes.

Helping maintain labs/gb

Discussion #5642 says the team is looking for new maintainers. I'd like to help maintain labs/gb over the long term. That means fixing issues, reviewing and testing changes, and keeping the components in line with the M3 spec as it changes. If there's a way to take that on, or to work on it in a more formal role, I'd be glad to talk about it.

I've applied for the CLA. Thanks for labs/gb. I built all of this on it.