fix(registry): apply components.build standard across all components

[jal-co]

Summary

Audit and fix all 20 registry components (20 files) against the components.build specification.

Changes by pillar

data-slot (data-attributes)

Added data-slot="<component-name>" on every exported sub-component root element. Enables stable parent-targeting:

<form className="[&_[data-slot=code-block]]:rounded-none">
  <CodeBlock code={...} />
</form>

Types (types)

• All prop interfaces now extend React.ComponentProps<"element">
• All root elements spread {...props} last
• Consumers can now pass id, aria-*, data-*, event handlers, and any native HTML attribute
• Removed standalone className props (inherited from ComponentProps)

Styling (styling)

• Removed decorative /* ---- */ separator comments from 4 files (ai-copy-button, code-block-client, log-viewer, stepper)

Accessibility (accessibility)

• FileTree: Full WAI-ARIA tree keyboard map — Arrow Up/Down (sibling nav), Arrow Left/Right (collapse/expand), Home/End (jump), all items focusable
• RequestViewer: Full WAI-ARIA tabs keyboard map — Arrow Left/Right (cycle tabs), Home/End (jump), roving tabIndex (only active tab in tab order)

State (state)

• CodeBlockCommand: Fixed hydration mismatch — moved localStorage.getItem() from useState initializer to useEffect, wrapped commands in useMemo for stable dependency

Verification

• pnpm lint — 0 errors, 0 warnings
• pnpm registry:build — all 20 items built
• pnpm build — 35/35 pages generated

Files changed

registry/activity-graph/activity-graph.tsx
registry/ai-copy-button/ai-copy-button.tsx
registry/api-ref-table/api-ref-table.tsx
registry/code-block-command/code-block-command.tsx
registry/code-block/code-block-client.tsx
registry/code-block/code-block.tsx
registry/code-line/code-line-copy-button.tsx
registry/code-line/code-line.tsx
registry/cron-schedule/cron-schedule.tsx
registry/diff-viewer/diff-viewer-client.tsx
registry/diff-viewer/diff-viewer.tsx
registry/env-table/env-table.tsx
registry/file-tree/file-tree.tsx
registry/json-viewer/json-viewer.tsx
registry/kbd/kbd.tsx
registry/log-viewer/log-viewer.tsx
registry/npm-badge/npm-badge.tsx
registry/request-viewer/request-viewer.tsx
registry/stepper/stepper.tsx
registry/tip-jar/tip-jar.tsx