[Accessibility] Desktop App: Screen reader cannot access AI thinking and tool call process during response generation

Description

When using a screen reader with the OpenCode Desktop App, it is not possible to accessibly browse the AI's thinking process, tool calls, and other intermediate steps while a response is still being generated. The streaming content is not exposed to the accessibility tree in real time, forcing screen reader users to wait until the entire response completes before they can review what the agent did.

Steps to Reproduce

1. Open OpenCode Desktop App with a screen reader running
2. Send a prompt that triggers tool calls or extended thinking (e.g., a task requiring file edits or multi-step research)
3. While the response is still streaming, attempt to use standard screen reader navigation (reading cursor / browse mode) to review the thinking and tool-call progress

Expected Behavior

• Screen reader users should be able to accessibly read and navigate the AI's thinking process, tool invocations, and their results as they are generated, without waiting for the full response to complete.
• Each intermediate step should be keyboard-navigable, properly labeled, and exposed via the accessibility tree.
• Dynamic updates should be announced via appropriate live regions without interrupting the user's ability to review previous steps.

Actual Behavior

• Thinking and tool-call information is inaccessible to screen readers during response generation.
• The content is either not exposed to the accessibility tree until the response finishes, or it cannot be reached via standard screen reader navigation while streaming.
• Users cannot monitor or verify what the agent is doing in real time.

Impact

This is a significant accessibility barrier for users who rely on screen readers. Without real-time access to the agent's actions, they cannot monitor progress, detect errors early, or build trust in the agent's behavior. This reduces the usability of the desktop app for this group of users.

Environment

• App: OpenCode Desktop App (BETA) v1.18.25
• OS: Windows 10 22H2 (also reproducible on higher versions of Windows)
• Assistive Technology: screen reader (latest version)

Suggestions

• Ensure streaming content (thinking, tool calls, status updates) is exposed via the proper accessibility tree with correct roles and names
• Use ARIA live regions (aria-live, aria-atomic, aria-relevant) to announce intermediate steps in real time, with polite to avoid interrupting navigation
• Make each intermediate step a focusable, collapsible section that is keyboard-navigable and properly labeled (e.g., role="region" with aria-labelledby)
• Allow reviewing each step (thinking / tool call / result) as it arrives, rather than only after completion
• Verify focus management does not trap or reset the screen reader cursor during streaming updates