fix(a11y): preserve report focus and data contrast

[seonghobae]

Buyer-visible outcome

Diagnostics reports retain readable data while users inspect a chart or table row, and the visually hidden skip-navigation link is reliably revealed whenever it actually receives focus.

Change

• reveal .skip-link on :focus as well as :focus-visible while retaining the strong visible outline;
• remove chart-peer and table-peer opacity selectors that dimmed unrelated active rows during pointer hover;
• keep the active-row background highlight, report data, generated markup, export transport, numerical values, and public Python APIs unchanged.

Verification

• render a realistic diagnostics report through the public render_diagnostics_report entry point;
• prove the generated stylesheet contains the actual-focus reveal rule and explicit outline;
• prove it contains neither opacity-based peer-dimming selector;
• retain complete repository Python, Rust/PyO3, GPU-no-skip, package, fuzz, Security Scan, and SAST validation;
• add APA 7th doctoring grounded in WCAG 2.2 and the January 22, 2026 Selectors Level 4 Working Draft;
• record the change in the authoritative changelog.

The exact rendered contrast depends on all computed colors and the rendering environment. This PR removes an avoidable contrast risk but does not make a formal WCAG conformance claim.

No Figma change is required for this bounded repair because it preserves the existing layout, color tokens, information architecture, and interaction model.

[google-labs-jules]

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[coderabbitai]

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📝 Walkthrough

Walkthrough

Diagnostics reports now reveal skip links on all focus states and no longer dim unrelated chart or table rows during hover. Regression tests, accessibility guidance, changelog entries, and standards references document the presentation-only changes.

Changes

Diagnostics report accessibility

Layer / File(s)	Summary
Report styling and regression coverage python/fast_mlsirm/report.py, tests/test_report_focus_contrast.py	Skip links receive visible styling for :focus and :focus-visible. Regression tests verify focus visibility and unchanged chart and table row colors.
Guidance and release documentation .Jules/palette.md, CHANGELOG.md, docs/changelog.d/..., docs/doctoring/...	Guidance and documentation describe the focus behavior, row contrast changes, verification scope, and WCAG 2.2 and Selectors Level 4 references.

Estimated code review effort: 2 (Simple) | ~10 minutes

Possibly related PRs

• ContextualWisdomLab/fast-mlsirm#526: Modifies related report accessibility CSS and regression tests.

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Docstring Coverage	✅ Passed	Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly summarizes the main accessibility changes: preserving focus visibility and data contrast in reports.

✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch palette-a11y-focus-contrast-9922568944841414864

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[coderabbitai]

Actionable comments posted: 1

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@tests/test_report_focus_contrast.py`:
- Around line 32-38: The test
test_skip_link_is_revealed_for_every_actual_focus_state should extract the CSS
body associated with the ".skip-link:focus,\n.skip-link:focus-visible {"
selector, then assert that this body contains both "top: 0" and the expected
outline declaration. Keep assertions scoped to this rule rather than searching
the entire stylesheet, preserving the documented focus-reveal contract.

🪄 Autofix

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

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📥 Commits

Reviewing files that changed from the base of the PR and between 84f3251 and c9142c9.

📒 Files selected for processing (6)

• .Jules/palette.md
• CHANGELOG.md
• docs/changelog.d/diagnostics-report-focus-contrast.md
• docs/doctoring/diagnostics-report-focus-contrast.md
• python/fast_mlsirm/report.py
• tests/test_report_focus_contrast.py

[seonghobae]

@coderabbitai review

@opencode-agent @cwl-noema-review Review exact head cc288bc173f3dd7578c4e06431a60a79351870b2. Verify that the generated diagnostics report reveals the skip link for actual :focus, retains a visible outline and non-destructive active-row hover cue, removes peer opacity dimming without changing report data or APIs, and makes no unsupported formal WCAG conformance claim. Confirm the public-renderer regression, APA 7 WCAG 2.2 and Selectors Level 4 doctoring, and authoritative changelog. Require current-head CI, Rust/PyO3, GPU no-skip, package, fuzz, Security Scan, SAST, zero actionable threads, and independent approval before merge.

[coderabbitai]

@seonghobae I will review PR #548 at head cc288bc173f3dd7578c4e06431a60a79351870b2.

I will verify the requested report behavior, regression coverage, doctoring references, changelog authority, API and data stability, conformance wording, current-head checks, review threads, and approval status.

⚠️ Action not completed

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[seonghobae]

Superseded by clean maintainer-owned PR #550. The automation-owned branch rewrote its head after review and discarded the scoped regression, doctoring, and changelog commits. PR #550 preserves the intended production change and addresses the CodeRabbit focus-rule scoping finding on a stable branch. Continue all verification and merge decisions on #550 only.

[google-labs-jules]

Superseded by clean maintainer-owned PR #550. The automation-owned branch rewrote its head after review and discarded the scoped regression, doctoring, and changelog commits. PR #550 preserves the intended production change and addresses the CodeRabbit focus-rule scoping finding on a stable branch. Continue all verification and merge decisions on #550 only.

Understood. Acknowledging that this PR has been superseded by #550 and is now obsolete. I will stop work on this task.