restore green check:quick baseline for notion-react workspace tasks

Context

• While validating the notion-react demo coverage work on branch schickling/2026-04-19-notion-react, repo quality gates were not clean before or after the demo changes.
• The new demo files pass targeted oxfmt, targeted oxlint, package unit tests, and Storybook build.
• Repo-wide ts:check / lint:check still fail on unrelated files.

Current failures

• ts:check fails in packages/@overeng/notion-react/src/renderer/sync-mock.unit.test.tsx because session fixtures no longer satisfy the Session type (id, title, body missing)
• lint:check reports existing warnings in packages/@overeng/notion-effect-client/src/blocks.ts (missing export JSDoc) and packages/@overeng/notion-react/src/renderer/sync-metrics.shape.unit.test.tsx (no-map-spread)

Follow-up

• restore a green devenv tasks run ts:check --mode before baseline
• restore a green devenv tasks run lint:check --mode before baseline
• keep the notion-react public demo work separate from these unrelated cleanup changes

Start with packages/@overeng/notion-react/src/renderer/sync-mock.unit.test.tsx and update the session fixtures to satisfy the reported Session type failure. Then inspect the warnings in packages/@overeng/notion-effect-client/src/blocks.ts and packages/@overeng/notion-react/src/renderer/sync-metrics.shape.unit.test.tsx. Run devenv tasks run ts:check --mode before and devenv tasks run lint:check --mode before; done means both checks pass.