[Bug]: Pi idle extension dialogs trigger false “work completed” notifications

### Operating system

Linux

### Orca version

1.4.200

### Details

Short summary:

Orca shows a “work completed” notification whenever I confirm a selection in a Pi extension dialog, even when no AI task is running.

What happened?

I encountered this with a custom `/yank` command that copies previous assistant messages or individual code blocks. It uses Pi’s standard `ctx.ui.select()` API for multiple steps:

1. Select an assistant message.
2. Choose full-message or code-block copying.
3. Select a code block.

A completion notification appears between selections. The built-in `/copy` command is unaffected because it copies directly without opening a dialog.

Environment:

- Orca: 1.4.200
- Pi running in an Orca-managed Linux container terminal
- Orca-managed `orca-agent-status.ts` integration enabled

Expected behavior:

Opening or closing an idle utility dialog should not trigger a “work completed” notification.

Notifications for real agent completion, questions, and approval requests should continue to work.

Actual behavior:

Confirming a Pi extension selection dialog triggers a “work completed” notification even though no agent turn is active.

How can we reproduce it?

1. Run Pi in an Orca-managed Linux container terminal with the Orca-managed `orca-agent-status.ts` integration enabled.
2. Use a Pi extension command that calls `ctx.ui.select()` while no AI task is running.
3. Confirm a selection in the dialog.
4. Observe that Orca shows a “work completed” notification.

Anything else that might help:

An offline replay of the installed Pi integration and Orca relay state mapping showed this sequence for each selection:

```text
ui_prompt_start
→ waiting

ui_prompt_end { is_idle: true }
→ done
```

Three dialog interactions produced three `done` states, with zero `agent_end` events.

The integration appears to forward UI prompt events even when no agent turn is in progress. The relay then maps `ui_prompt_end` with `is_idle: true` to `done`, which can trigger a false completion notification.

The desktop notification dispatch itself was not replayed offline; the visible notifications were observed during real `/yank` usage.

Suggested fix:

Distinguish idle utility dialogs from prompts associated with an active agent turn.

One possible fix is to ignore `ui_prompt_start` when `piTurnInFlight` is false, while preserving balanced handling for dialogs opened during an active turn.

An in-memory trial of this change suppressed the false completion states while retaining:

- Waiting/working states for questions during an agent turn.
- One completion state when the agent actually finishes.
- Correct completion when an agent finishes while a dialog remains open.

Any permanent fix should update Orca’s extension-generation source, not only the generated local extension.

Start with the Orca-managed orca-agent-status.ts integration and trace ui_prompt_start, ui_prompt_end, agent_end, and piTurnInFlight through the relay state mapping. Verify the fix in an idle Pi ctx.ui.select() dialog and during an active agent turn, including a dialog that remains open when the agent finishes; done means no false completion notification and one real completion state.

Written by the indexing model from the issue text.