fix(remote-react-components): scope cross-version refs per test file

[mfal]

Problem

The scheduled Run scheduled visual tests workflow's cross-version job has failed on every run since it was introduced (2026-07-21) — specifically the in-process harness, with a Checkbox edge cases(CrossVersion) structural-snapshot mismatch against the previous published version.

It is not a version incompatibility. The in-process harness keyed each ephemeral reference HTML file only on testName + description:

`${REF_DIR}/${slugify(`${testName}-${description}`)}.html`

Two reused visual tests share the exact name "Checkbox edge cases":

• Checkbox.browser.test.tsx → renders one <Checkbox> (7-tag tree)
• CheckboxButton.browser.test.tsx → renders a Flex with two <CheckboxButton>s (18-tag tree) — the test is mis-named "Checkbox edge cases"

Both therefore read and write the same .refs/*.html file. Whichever test writes the reference last makes the other's comparison mismatch. This is deterministic (it failed on the job's very first scheduled run and every one since), and unrelated to the actual old version — current and the compared version render identically once the tests are keyed apart.

The normal visual screenshot suite does not hit this because vitest scopes screenshots per test file (__screenshots__/<file>/…); only the cross-version harness used a flat, non-file-scoped key.

Fix

Include the source-file basename in the reference key, mirroring vitest's own per-file screenshot scoping. Small, self-contained change to crossVersionEnvironment.tsx. This resolves the collision and prevents any future same-name collision.

Validation

• Installed @mittwald/flow-remote-react-components@0.2.0-alpha.932 locally and reproduced the failure via the full 83-file corpus.
• After the fix: full-corpus comparison vs alpha.932 → 167/167 pass, run twice, deterministically green; the reference pass now writes two distinct edge-case files instead of one.
• test:compile (tsc), ESLint, and Prettier all clean.
• No impact on the visual suite or committed screenshots — the .refs are wiped and regenerated on every run.

Notes for reviewers

• Supersedes the approach in Stabilize cross-version CI by skipping incompatible CheckboxButton edge-case snapshots before alpha.933 #2683, which bumps the cross-version skip watermark. That treats this harness bug as a version break (and targets alpha.933, a docs-only release that renders identically to 932), so it would not durably fix the failure.
• Optional follow-up: rename the CheckboxButton test from "Checkbox edge cases" to "CheckboxButton edge cases" for clarity. Left out here because the description also names that test's committed visual screenshot baselines (CheckboxButton.browser.test.tsx/Checkbox-edge-cases-*.png), so renaming would require regenerating those (including the Linux baseline via the update-screenshots label). The file-scoping fix makes the duplicate name harmless regardless.
• Separate, pre-existing flake (out of scope): the iframe step's Button scenarios intermittently hit ~180–240s @quilted/threads connection-timeout hangs; the workflow's retry loop usually absorbs it.

🤖 Generated with Claude Code

[github-actions]

Coverage Report for ./packages/components/

Status	Category	Percentage	Covered / Total
🔵	Lines	78.09%	328 / 420
🔵	Statements	78.08%	335 / 429
🔵	Functions	81.72%	76 / 93
🔵	Branches	66.81%	151 / 226

File Coverage

No changed files found.

Generated in workflow #5727 for commit 0f9003b by the Vitest Coverage Report Action

[github-actions]

🚀 Preview Deployment

Preview environments are ready:

Type	URL
docs	pr-2688.docs.review.flow-components.de
storybook	pr-2688.storybook.review.flow-components.de

Images:

• docs: ghcr.io/mittwald/flow/docs:pr-2688
• storybook: ghcr.io/mittwald/flow/storybook:pr-2688