Add v8 coverage via a test:coverage script and vitest config: measure src
only, exclude the types-only deps.ts and the bin entrypoint main.ts, and
gate on ratcheted thresholds (statements 85, branches 78, functions 90,
lines 85) set just under current coverage. CI runs the unit+integration
tier through coverage so a real drop fails the build.
Add the end-to-end test tier: a Gitea Actions workflow (GitHub-compatible)
that runs the unit+integration tiers plus e2e tests against a pinned
disposable Gitea service container. The e2e suite provisions its own repo,
token, and seed data over HTTP and drives the real CLI seam, gated on
GITEA_AXI_E2E_URL so the default suite stays dependency-free.
A fixture-vs-live shape guard anchors the issue-list FieldDef paths against
both the recorded fixture and the live response, failing on divergence.
