Delete Async Chat Stream

Delete an asynchronous chat stream and clean up all associated resources.

This endpoint permanently removes a chat stream from storage and cleans up all associated resources including:

• Stream metadata and status information
• Cached events and message content
• Task references and cancellation tokens

Notes:

• Stream must exist to be deleted (returns 404 otherwise)
• Active streams are automatically cancelled before deletion
• No response body returned on successful deletion (204 status)
• Use status endpoint to verify deletion if needed