D-27: Dialogue — accessibility sweep (9-point checklist)

[kirich1409]

Description

Full accessibility pass over every view added by the Dialogue feature. Apply the 9-point checklist from the global DS rule (CLAUDE.md §Design System) and run the manual audit workflow.

Spec: Epic #250 §9 acceptance criterion 8; CLAUDE.md §Design System → Accessibility checklist.

Scope

Views to cover

All new views added through D-1 through D-26:

• Card, StatusIndicator, BlockCodeContainer (DS primitives — a11y at component level)
• DialogueView, UserMessageView, AssistantMessageView
• DialogueMarkdownView (rendered markdown)
• ToolCallCardView + all 12 specialized widgets
• ThinkingIndicatorView
• StreamInspectorView
• PreflightErrorView

9-point checklist — per view

1. .accessibilityLabel — concise noun.
2. .accessibilityHint — for non-trivial actions.
3. .accessibilityValue — for stateful controls.
4. .keyboardShortcut — on primary actions (⌘Return, ⌘., ⌘⇧D, ⌘⇧T, ⌘⌥R).
5. .focusable() + .contentShape(_:) on custom controls.
6. Colour never sole signal — SF Symbol + accessibilityDifferentiateWithoutColor.
7. Animations wrapped in accessibilityReduceMotion guard (re-verify every pulse/shake/spring).
8. Materials respect accessibilityReduceTransparency.
9. Icon-only buttons have .accessibilityLabel.

Manual audit (per CLAUDE.md workflow)

1. Accessibility Inspector — open Debug Relay.app, step through Dialogue flows:
   • Create new Dialogue session
   • Watch assistant stream + tool calls
   • Open Stream Inspector
   • Open as Terminal action
   • Preflight error path
     Record + resolve every warning.
2. VoiceOver sweep (⌘F5) — navigate each flow with arrow keys only. Every element must announce meaningfully.
3. Dynamic accessibility — toggle Reduce Motion, Reduce Transparency, Increase Contrast one at a time; re-open app; verify animations, materials, colors adapt.
4. Keyboard-only — disconnect mouse; tab through all interactive elements; verify focus ring visibility.

Fixes

Fix any issues discovered. Non-blocking polish — open follow-up issues.

Acceptance Criteria

• 9-point checklist verified on every listed view (tracked in PR description).
• Accessibility Inspector audit: no warnings on Dialogue flows in Debug build.
• VoiceOver sweep: every flow completable without mouse.
• Reduce Motion: no pulses / shakes / springs — only fade or static.
• Reduce Transparency: no see-through materials in Dialogue chrome.
• Increase Contrast: every signal distinguishable (SF Symbol + tone).
• Keyboard-only: every primary action reachable via ⌘-shortcut or Tab + Return.
• PR description lists all findings + fixes (or follow-up issues).

Relationships

• Parent issue: EPIC: Dialogue — structured chat UI for agent sessions #250
• Blocked by: #D-18, #D-19, #D-23, #D-25, #D-26 (all integrated UI)
• Blocks: release (MVP acceptance criterion 8)