test(components): backfill flow mdx coverage

[bntvllnt]

Related to #231

Summary

• Add TutorialMDX coverage for plain markdown rendering, fenced JSX markdown handling, MDX component rendering, lazy FlowDiagram mapping, and exported tutorial component keys.
• Add FlowDiagram coverage with mocked React Flow runtime for rendering, hidden controls, validation warnings, zoom/fit/node-click wiring, fullscreen portal behavior, and copy-to-clipboard image flow.

Validation

• pnpm -F @vllnt/ui exec vitest run src/components/tutorial-mdx/tutorial-mdx.test.tsx src/components/flow-diagram/flow-diagram.test.tsx (2 files, 11 tests)
• pnpm -F @vllnt/ui exec eslint src/components/tutorial-mdx/tutorial-mdx.test.tsx src/components/flow-diagram/flow-diagram.test.tsx
• pnpm -F @vllnt/ui lint
• pnpm -F @vllnt/ui exec tsc --noEmit --project tsconfig.build.json
• pnpm build
• pnpm test:once (218 files, 1226 tests)
• pnpm -F @vllnt/ui check:use-client
• pnpm -F @vllnt/ui check:stories
• pnpm -F @vllnt/ui storybook:verify
• pnpm -F @vllnt/ui build-storybook
• git diff --check
• git diff --cached --check

CI status update (2026-05-19T06:45:30Z)

Current head: f771aae6b7439d7fe9b6ba16a120487898649e29

• GitHub Actions build · sign · scan · deploy: PASS: build · sign · scan · deploy is green at the current head.
• vllnt-pilot preview/deploy status: PASS: vllnt-pilot / preview deploy succeeded at https://pr-354-ui-registry.preview.vllnt.ai. The stale legacy blank vllnt-pilot check-run with old buildctl-missing output is superseded/neutralized separately.
• Other current PR checks observed green: Quality Gates, CodeQL, issue-link enforcement, story verification, Storybook build/tests, visual regression, codebase health, and CodeQL language analyses.
• Merge/release status: not merged; current disposition is manual-review-ready only after the deployer/preview status is green at the same head.

[vllnt-pilot]

Preview ready · pr-354-ui-registry

Service	Status	Preview
ui-registry	Ready	https://pr-354-ui-registry.preview.vllnt.ai

Inspect

• Deployed to vllnt-cluster from f771aae
• Reply with /clean to destroy this preview now

[bntvllnt]

Review — manual approval recommended

I reviewed the full diff at head f771aae and found no blocking issues.

Coverage reviewed:

• packages/ui/src/components/flow-diagram/flow-diagram.test.tsx
• packages/ui/src/components/tutorial-mdx/tutorial-mdx.test.tsx

Verified clean:

• FlowDiagram tests cover rendering, controls, validation warnings, interaction callbacks, fullscreen portal behavior, and copy-to-clipboard image flow against the current implementation.
• TutorialMDX tests cover markdown rendering, fenced JSX handling, MDX component rendering, lazy FlowDiagram mapping, and exported component-map keys.
• PR body contains the test: backfill Vitest coverage for components shipped without tests #231 issue link and matches the current green check status.
• GitHub checks were re-fetched at review time: required checks were passing at the reviewed head, with one neutral/skipping superseded legacy preview check. Full changed-file diff coverage was completed; local reruns were treated as supplementary where available.

Manual approval boundary:
Approval is recommended, but final APPROVE is reserved for bntvllnt/manual review by policy. Because this PR is authored by the authenticated reviewer account, this top-level PR comment is the authoritative Jarvis clean/manual-ready fallback artifact rather than a formal self-approval.

[bntvllnt]

Review — manual approval recommended

@bntvllnt I re-reviewed PR #354 at head f771aae6b7439d7fe9b6ba16a120487898649e29 and found no blockers.

BLOCKING

None.

WARN

None.

VERIFIED CLEAN

• Current live state verified: open, non-draft, mergeStateStatus: CLEAN, mergeable: MERGEABLE, changedFiles=2, head matches the assigned SHA.
• Full changed-file coverage reviewed:
  • packages/ui/src/components/flow-diagram/flow-diagram.test.tsx
  • packages/ui/src/components/tutorial-mdx/tutorial-mdx.test.tsx
• Reviewed surrounding component behavior for FlowDiagram validation warnings, controls, fullscreen portal, image-copy flow, and TutorialMDX markdown/MDX component/lazy FlowDiagram rendering.
• Rule verdicts: PASS R3 PR body freshness; PASS R5 issue link (Related to #231); PASS issue #231 test-only scope; PASS generated-artifact policy (none touched); PASS no shipped-code comments/runtime changes; PASS local targeted coverage validity.

VALIDATION

• Ran locally in the PR worktree: pnpm exec vitest run src/components/flow-diagram/flow-diagram.test.tsx src/components/tutorial-mdx/tutorial-mdx.test.tsx — 2 files, 11 tests passed.
• Live checks observed: issue-link enforcement, preview deploy, build/sign/scan/deploy, Storybook, visual regression, CodeQL, health scan, quality gates, and story verification all pass; only the superseded legacy preview check is neutral.

Verdict: no blockers. Approval is recommended, but final approval is reserved for bntvllnt per review policy.