Add Copilot Chat dictation

[Mir (mirimadahmed)]

No description provided.

[Copilot]

Pull request overview

Adds hosted Copilot Chat dictation with shared microphone ownership, editable transcripts, accessibility feedback, Agents window support, and tests.

Changes:

• Adds remote transcription, audio capture, endpoint, and session-control services.
• Integrates dictation actions, state, notifications, accessibility help, and Agents UI.
• Adds coverage for protocol, lifecycle, editing, endpoint, and lease behavior.

Reviewed changes

Copilot reviewed 27 out of 27 changed files in this pull request and generated 6 comments.

Show a summary per file

File	Description
voiceClientService.test.ts	Tests terminal WebSocket failures.
voiceEndpoint.test.ts	Tests endpoint derivation and authentication.
voiceCodeTranscriptionClient.test.ts	Tests transcription protocol handling.
remoteChatSpeechToTextService.test.ts	Tests remote dictation lifecycle.
dictationSession.test.ts	Tests transcript editor behavior.
audioCaptureLeaseService.test.ts	Tests encoding and lease exclusivity.
chatDictationNotification.test.ts	Tests first-use notification persistence.
common/voiceClientService.ts	Adds terminal-connection event API.
common/constants.ts	Adds dictation configuration key.
chatContextKeys.ts	Adds starting and finalizing states.
voiceSessionController.ts	Coordinates microphone leases and termination.
voiceEndpoint.ts	Builds voice and transcription URLs.
browser/voiceClientService.ts	Handles terminal WebSocket failures.
audioCaptureLeaseService.ts	Enforces exclusive microphone ownership.
voiceCodeTranscriptionClient.ts	Implements hosted transcription protocol.
remoteChatSpeechToTextService.ts	Orchestrates remote dictation.
dictationSession.ts	Manages editable transcript insertion.
dictationAudioCapture.ts	Captures and encodes microphone audio.
chatSpeechToTextService.ts	Selects local or remote transcription.
chatDictationNotification.ts	Adds first-use guidance.
chat.shared.contribution.ts	Registers settings, services, and contribution.
chatSpeechToTextActions.ts	Adds dictation actions and states.
chatAccessibilityHelp.ts	Documents dictation accessibility workflow.
sessions/LAYOUT.md	Documents Agents dictation integration.
newChatInput.ts	Adds shared dictation controls to Agents.
package.nls.json	Adds localized walkthrough copy.
package.json	Registers the dictation walkthrough.

[Megan Rogge (meganrogge)]

We will consider this after seeing usage of dictation and continue to think about the who would pay part.

[Megan Rogge (meganrogge)]

Handling myself due to merge conflicts and all the changes that have occurred. Thanks!