Support OSC 8 hyperlink sequences for file paths and URLs in TUI output

Problem

Claude Code outputs absolute file paths and URLs in its TUI, but they're not clickable. Modern terminals (Ghostty, iTerm2, WezTerm, Kitty) support OSC 8 hyperlink escape sequences — inline clickable links embedded directly in terminal output.

Since Claude Code's TUI captures all mouse events, the terminal's native URL detection (hover + Cmd/Ctrl) can't work. OSC 8 is the standard way TUI apps solve this — the terminal recognizes the escape sequence regardless of alternate screen buffer or mouse capture mode.

Expected behavior

File paths like /Users/me/project/src/app.ts:42 and URLs like https://github.com/org/repo/pull/1 in Claude Code output should be Cmd+clickable (macOS) / Ctrl+clickable (Linux) to open in the default editor or browser.

Proposed solution

Wrap file paths and URLs in OSC 8 sequences:

\e]8;;file:///Users/me/project/src/app.ts\e\\path/to/file.ts:42\e]8;;\e\\
\e]8;;https://github.com/org/repo/pull/1\e\\PR #1\e]8;;\e\\

This is already the approach used by tools like ls --hyperlink, gcc, and systemd for terminal-native link support.

Context

• Claude Code already outputs absolute paths (configurable in CLAUDE.md) specifically to enable terminal click-to-open
• The PR status footer already has a clickable link — extending this to all paths/URLs would be consistent
• Terminals that don't support OSC 8 simply ignore the sequences — zero visual impact on older terminals