UI auto-links #xxx to /issues/xxx instead of /pull/xxx

Description

When Claude Code output contains #123 style references (e.g. referencing a GitHub PR number), the UI auto-links them to https://github.com/{owner}/{repo}/issues/123 instead of https://github.com/{owner}/{repo}/pull/123.

On GitHub, issues and PRs share the same number space. When the referenced number is a Pull Request, the link should point to /pull/123, not /issues/123.

Steps to Reproduce

1. Work in a repository context (e.g. OEN-Tech/app)
2. Have Claude output text containing #19553 referencing a PR
3. The UI renders it as a clickable link to https://github.com/OEN-Tech/app/issues/19553
4. The correct URL should be https://github.com/OEN-Tech/app/pull/19553

Expected Behavior

• Either link to /pull/xxx when the number is a PR, or use a neutral URL that GitHub will redirect correctly (GitHub does redirect /issues/xxx to /pull/xxx for PRs, but the displayed URL is still incorrect and confusing)
• Alternatively, do not auto-link #xxx patterns at all and let users provide explicit URLs

Environment

• Claude Code CLI
• macOS