Make provenance subordinate to human reading

[erinepshovel-code]

What changes

• Article Lab labels are now literal: Article and Footnotes; Speaker A / Speaker B are removed from the Lab UI
• Lab source/provenance is hidden in a collapsed Source & provenance disclosure beneath the Article
• the Lab index no longer describes Article text and footnotes as speakers
• Preamble provenance is collapsed after the canonical text
• textbook chapter provenance is collapsed after chapter content instead of preceding it
• the legacy /start/ orientation page is renamed Site orientation and no longer describes Article/Footnotes as speakers
• the global navigation already names its destination The Way rather than Start; the stale Start · Way tree breadcrumb is removed
• the eight legacy publication Article routes are normalized at build time to render Article, Footnotes, and collapsed Source & provenance without requiring browser JavaScript
• previous/next/Way links that were entangled with legacy Article provenance are kept visible outside the collapsed disclosure

Invariants preserved

• canon wording/order is unchanged
• source/provenance remains available for verification
• machine-readable discovery remains unchanged
• textbook source identity and authority boundaries remain intact
• research data and Article Lab interpretation remain distinct from canon

Tests

• source contract now witnesses literal Article/Footnotes labels, collapsed provenance, and destination-named navigation
• new tests/human-ui-generated.test.mjs checks the rendered Preamble, textbook, Article Lab, publication Article, orientation page, and navigation
• the generated witness is included in npm run test:generated

Validation boundary

The contracts are wired. GitHub's Pull Request workflow is running on the current head; keep this draft until execution witnesses pass, including browser/accessibility checks where available.