Add POST /workflow/stories/create endpoint that auto-assigns story
numbers, generates correct front matter, and writes to upcoming/.
Add slugify_name and next_story_number helpers with full test coverage.
Add frontend createStory API method and types.
Update README to recommend creation API for agents.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Add end-to-end coverage tracking: backend collects vitest coverage,
records metrics with threshold/baseline tracking, and blocks acceptance
on regression. Frontend displays coverage in gate/review panels with
a "Collect Coverage" button. Includes 20 Rust tests, 17 Vitest tests,
and 14 Playwright E2E tests.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
