[Accessibility] Complete keyboard, focus, and shortcut behavior in Theme Manager

[rwang23]

[Accessibility] Complete keyboard, focus, and shortcut behavior in Theme Manager

Draft status: ready to create; not submitted by the audit run.
Priority: P1
Findings: ACT-016, ACT-017, ACT-018, ACT-033

Summary

Theme Manager declares dialog, tab, listbox, and option semantics, but the corresponding keyboard/focus model is incomplete. A global Ctrl/Cmd+C shortcut can also override normal text copying, and several important labels/status messages are rendered at very small sizes.

中文摘要：Theme Manager 已声明复杂 ARIA 语义，但没有完整实现对应键盘交互；授权弹窗缺少焦点隔离/恢复，全局复制快捷键可能覆盖正常复制，小字密度也偏高。需要按原生控件或 APG 完整实现。

Audit evidence

• The persistence consent UI is a custom div role="dialog"; the code focuses the confirm button but does not provide a full focus trap, background inert state, or focus restoration.
• tablist, tab, listbox, and option roles are present without complete Arrow/Home/End/roving-tabindex/tabpanel behavior.
• Global Ctrl/Cmd+C may trigger “copy theme” outside the search box without first checking the current text selection or all editable/control contexts.
• The repository screenshot and CSS show dense secondary metadata and some labels/status/consent copy around 7–10 px.

Proposed direction

• Prefer native <dialog> and ordinary buttons/lists when composite-widget behavior is not necessary.
• If tabs/listbox semantics remain, implement the full WAI-ARIA Authoring Practices keyboard and focus model.
• Centralize shortcut context checks and do not intercept platform copy when text is selected or focus is editable/control/dialog content.
• Raise essential text and risk-copy sizes; move full hashes/provenance details into secondary disclosure.
• Add automated keyboard and axe tests plus manual NVDA/VoiceOver/high-contrast checks.

Acceptance criteria

• Consent uses native <dialog> or an equivalent fully tested focus trap with background inert, Escape behavior, safe initial focus, and trigger focus restoration.
• Tabs/listbox either implement Arrow/Home/End/typeahead/roving tabindex/selection correctly or are replaced with simpler native semantics.
• All primary flows—search, filter, theme select, mode switch, Apply/Keep consent, cancel, Restore, diagnostics—are keyboard-completable.
• Ctrl/Cmd+C preserves normal copy whenever there is a non-collapsed selection or focus is in an editable/control/dialog context; any theme-copy shortcut is documented and conflict-free.
• Focus remains visible in default, forced-colors/high-contrast, and reduced-motion modes.
• Essential body/risk/status text remains readable at 125%, 150%, and 200% scaling and in a smaller supported window.
• Automated tests include focus order, dialog containment/restoration, composite keyboard behavior, shortcut context, and axe serious/critical checks.
• Accessible names and error/status messages participate in the existing language switch.

Related audit findings

ACT-016, ACT-017, ACT-018, ACT-033.

Reference snippets are available in demo/ui/accessible-consent-dialog.html, demo/ui/accessible-dialog.js, and demo/ui/roving-listbox.js in the audit bundle.

[rwang23]

The automated accessibility remediation landed in #26. The current Theme Manager accessibility check passes dialog focus behavior, keyboard select/apply/cancel/restore, shortcut context, forced-colors/reduced-motion checks, and axe serious/critical scans.

The remaining acceptance work is a recorded manual check at 125/150/200% scaling and on the supported OS assistive-technology paths. Keeping this Issue open until those real-renderer checks are captured.