Wrapped links leak OSC 8 escape markup in Ghostty

### Describe the bug

Long links in assistant Markdown sometimes render with the OSC 8 hyperlink control payload visible as text when the link wraps in Ghostty. The output is prefixed with text resembling:

```text
]8;;id=md-;https://example.com/a/very/long/path/https://example.com/a/very/long/path/
```

The saved assistant response contains only a valid plain URL, with no malformed Markdown or escape sequences. This indicates the corruption occurs in Copilot CLI's terminal rendering rather than in model output.

This appears related to the `1.0.68` changelog fix, "Preserve wrapped OSC 8 hyperlink IDs in terminal output," but still reproduces on `1.0.78`.

### Affected version

```text
GitHub Copilot CLI 1.0.78
```

### Steps to reproduce the behavior

1. Launch Copilot CLI in Ghostty.
2. Have an assistant response end with a bare URL long enough to wrap at the current terminal width.
3. Observe that the URL is preceded by visible OSC 8 payload text such as `]8;;id=md-...;` and may appear duplicated.

An affected session is:

```text
250a0930-cde5-4f39-bcdd-c40ef05656a0
```

The problem is visible in the final assistant response of that session.

### Expected behavior

The response should display one clean, clickable URL. OSC 8 control sequences and generated hyperlink IDs must never be visible, including when the URL wraps across terminal lines.

### Additional context

- Operating system: macOS (Darwin), Apple Silicon
- Terminal: Ghostty `1.3.2-main-+8252871b2`
- Environment: `TERM_PROGRAM=ghostty`, `TERM=xterm-ghostty`, `COLORTERM=truecolor`
- Workaround: launching with `FORCE_HYPERLINK=0 copilot` prevents OSC 8 hyperlinks from being emitted
- The local session event log records the assistant content as normal prose followed by a plain URL, confirming the malformed text is introduced during rendering
- Screenshot exists locally but was not attached because `gh issue create` does not support uploading issue-form attachments

Riproduci il problema eseguendo Copilot CLI 1.0.78 in Ghostty con un lungo URL semplice che va a capo, usando la sessione 250a0930-cde5-4f39-bcdd-c40ef05656a0 come contesto. Confronta l’URL semplice nel registro degli eventi della sessione con l’output del terminale e traccia il percorso di rendering di OSC 8; il lavoro è completato quando i link che vanno a capo vengono visualizzati come un unico URL pulito e cliccabile, senza payload di controllo visibili né testo duplicato.

Scritto dal modello di indicizzazione a partire dal testo della issue.