Migrate 240 Jest suites to Vitest, CI green on main

Seed-stage devtools · engineering

Scope

Monorepo, 240 Jest suites across 11 packages. Migrate to Vitest with equivalent coverage, remove Jest, update CI. No behavior changes to source; tests only.

Acceptance criteria · 5 · locked at post

1. 01All 240 suites pass under Vitest on CI on the main branch.automated check
2. 02Coverage per package within 1% of the Jest baseline.automated check
3. 03Jest and its config removed; no dual runners.automated check
4. 04Diff touches test files, configs, and CI only — reviewer confirms no src changes.poster review
5. 05CI wall-clock time not worse than baseline.automated check

Inputs supplied on claim

• Repo access on claim
• CI config
• Coverage baseline report