[TheGreatAxios]

PR #795 moved the chat feed adapter to native GET /me/inbox/threads, retiring the /me/threads?refs= route and the old chat-send shape. This left 34 chat-ui DOM test cases failing because their fixtures mocked the retired route/shape. Per owner ruling, these are deleted outright rather than patched to keep passing.

Deleted:

• packages/chat-ui/test/stream-message-parse-drop.test.tsx
• packages/chat-ui/test/zero-refetch-on-stream-event.test.tsx
• The following failing describe blocks from packages/chat-ui/test/chat-workspace.test.tsx (file kept, since two of its describe blocks still pass against the current route/shape and were left in place):
  • ChatWorkspace settings surface
  • connection state is never rendered as chrome
  • Thread breadcrumb and fork (CL-5908, CL-5948)
  • hover Edit copies an own prompt into the composer
  • composer slash commands — each wired command's real action
  • a workbench-level 404 offers a way out instead of retrying forever
  • a 401 on the messages load offers Sign in instead of a dead-end retry
  • optimistic send (CL-6103)
  • refresh ordering around a send (CL-6251, CL-6313)
  • Workbench header polish (CL-6106)
  • CL-6833: running-turn resume failure is visible, never silent idle
  • switching workbenches never carries a stale root-thread id across

Kept (still green, unrelated to the retired route): chat error copy never leaks a raw API path, Invite control visibility (CL-6781).

Recorded on CL-8150 for selective rebuild against the new mailbox-thread shape.

Test plan

• bun test in packages/chat-ui: 802 pass, 0 fail
• bun run typecheck at repo root: clean
• bun run lint at repo root: clean

[linear-code]

CL-8150