[iOS Remote] Successful single-file apply_patch omits the changed-files card

Start with emit_patch_end in codex-rs/core/src/tools/events.rs and the fileChange and turn/diff/updated protocol sections in codex-rs/app-server/README.md. Check whether the public server emits the expected events for a single added Markdown file and whether a reproducible server-side issue is possible; completion requires identifying the missing event or confirming that the failure is confined to unavailable iOS client rendering or replay.

What issue are you seeing?

In a Codex Remote conversation viewed from the ChatGPT iOS app, a successful single-file apply_patch did not produce the expandable “1 file changed” card beneath the assistant response.

A prior turn in the same remote conversation changed eight net files and did show the expected “8 files changed” card; its rows were clickable and loaded the host-backed files. The missing-card turn added one ordinary Markdown file inside the active workspace.

This is separate from Markdown file-link rendering. In the same iOS client:

• absolute Markdown targets work, with and without a line suffix;
• an angle-wrapped absolute target works equivalently;
• workspace-relative Markdown targets do not resolve;
• bare paths and inline-code paths are not clickable.

The current model instructions already prefer absolute Markdown links, so those links are a workable citation format for workspace files. They are not a substitute for the structured changed-files card, which provides the diff and change summary.

What steps can reproduce the bug?

1. Connect the ChatGPT iOS app to a Codex Remote host.
2. Start a thread with a workspace on the host.
3. Have Codex add one small text or Markdown file using apply_patch.
4. Confirm that the host file exists and the tool completed successfully.
5. Finish the turn.
6. Observe that no expandable “1 file changed” card appears below the final response.

Control observation: a turn in the same thread with eight net file changes displayed the card correctly.

Host-side evidence for the missing-card turn was persisted in the rollout as a successful terminal event with one added file:

{
  "type": "patch_apply_end",
  "success": true,
  "status": "completed",
  "changes": {
    "/home/user/workspace/example.md": {
      "type": "add"
    }
  }
}

Environment:

• ChatGPT iOS app, Codex Remote
• Remote host: Linux
• Host Codex CLI: 0.146.1
• Observed: 2026-08-05

I can provide the session identifier privately if it would help correlate client telemetry.

What is the expected behavior?

Every successful non-empty fileChange should render the changed-files summary/card, including a turn whose net result is one newly added non-HTML file. It should remain available after the turn completes and after reconnect/replay.

Additional information

The open-source app-server path appears to have completed correctly:

• emit_patch_end first emits a completed FileChangeItem, then sends TurnDiff when the tracked diff is non-empty: https://github.com/openai/codex/blob/0c07c7ee47612715d29b2523a1522ed68daa421f/codex-rs/core/src/tools/events.rs#L603-L654
• The protocol documents fileChange as a normal thread item: https://github.com/openai/codex/blob/0c07c7ee47612715d29b2523a1522ed68daa421f/codex-rs/app-server/README.md#L1535-L1544
• It also documents turn/diff/updated as the snapshot clients can use for the full “what changed” UI: https://github.com/openai/codex/blob/0c07c7ee47612715d29b2523a1522ed68daa421f/codex-rs/app-server/README.md#L1520-L1530

The public repository contains the Rust app-server/TUI but not the iOS Remote presentation code, so the likely failure point is client rendering, event consumption, or replay/aggregation rather than patch execution.

I searched the open tracker before filing. #19566 is similar but specific to a single HTML file in the VS Code extension, while #17963 concerns incomplete multi-file contents in the desktop Review panel; neither covers this iOS Remote + single Markdown file case.