Wrapped links leak OSC 8 escape markup in Ghostty #4356

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:

]8;;id=md-<generated-id>;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

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:

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