[A11y bug] Missing heading semantics and "response complete" announcements in desktop app

Summary

The Claude Code desktop app does not provide the heading structure or response-completion cues that the Claude.ai web app provides. This is a regression in accessibility parity between two surfaces of the same product.

Impact

As a blind VoiceOver user, in the Claude.ai web app I can:

• Use VoiceOver rotor to jump between headings in a response.
• Hear a clear announcement when Claude has finished streaming a response.

In the Claude Code desktop app, neither of these works. Claude's output appears as flat text with no navigable heading landmarks, and there is no reliable cue that the response is complete. I end up arrow-keying through the entire output or guessing when it's safe to start typing again.

Expected

• Markdown headings in Claude's response render as proper heading landmarks (H1/H2/H3) so VoiceOver rotor can navigate them.
• A clear announcement (live region, system notification, or focus change) fires when Claude finishes streaming a response, matching the Claude.ai behavior.

Context

I submitted the same feedback via the in-app /feedback channel and to support@anthropic.com so the team can dedupe.

I am Lead Accessibility Architect at Paramount Streaming. Happy to test fixes.