Improve automatic thread naming in the TUI (#42749)

## Why

Automatic title generation used a provisional thread name and only applied the
generated result while its thread remained active. Switching threads could
therefore leave the originating thread without its generated name.

## What changed

- Track title-generation requests by thread so results are persisted for the
  originating thread, while preserving any name set before generation finishes.
- Show a `renaming...` spinner instead of a provisional name, including across
  thread switches and failure paths.
- Add `thread-name` items to the status line and terminal title, and include the
  generated thread name in both default layouts.

## Testing

- Cover automatic naming, manual-name precedence, thread switching, failed
  requests, deduplication, and status-surface rendering and animation.

GitOrigin-RevId: a03ae4849bedec9f62f256fadad72c1685ce46e0

codex-rs/core/config.schema.json

@@ -4115,7 +4115,7 @@
         },
         "status_line": {
           "default": null,
-          "description": "Ordered list of status line item identifiers.\n\nWhen set, the TUI renders the selected items as the status line. When unset, the TUI defaults to: `model-with-reasoning` and `current-dir`.",
+          "description": "Ordered list of status line item identifiers.\n\nWhen set, the TUI renders the selected items as the status line. When unset, the TUI defaults to: `model-with-reasoning`, `current-dir`, and `thread-name`.",
           "items": {
             "type": "string"
           },
@@ -4135,7 +4135,7 @@
         },
         "terminal_title": {
           "default": null,
-          "description": "Ordered list of terminal title item identifiers.\n\nWhen set, the TUI renders the selected items into the terminal window/tab title. When unset, the TUI defaults to: `activity` and `project`. The `activity` item spins while working and shows an action-required message when blocked on the user.",
+          "description": "Ordered list of terminal title item identifiers.\n\nWhen set, the TUI renders the selected items into the terminal window/tab title. When unset, the TUI defaults to: `activity`, `thread-name`, and `project-name`. The `activity` item spins while working and shows an action-required message when blocked on the user.",
           "items": {
             "type": "string"
           },