TUI /login is uncompletable: auth URL won't auto-open and 'c' won't copy it (mouse-capture blocks manual selection)

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report
• [x] I am using the latest version of Claude Code

Environment

• Claude Code: 2.1.195 (npm-global, @anthropic-ai/claude-code)
• OS: macOS (Darwin 25.5.0), Apple Silicon
• Auth: claude.ai subscription (OAuth)
• Running in a normal local terminal (not SSH/tmux).

What's Wrong?

When the TUI drops you into the /login screen, there is no working way to follow the login URL, so login cannot be completed from inside the TUI:

1. The login URL does not auto-open a browser — even though $BROWSER is empty (so it should fall back to open) and open https://anthropic.com opens the default browser fine from the same shell.
2. The "press c to copy" shortcut does not put the URL on the clipboard — nothing is copied, so it can't be pasted into a browser either.
3. Manual selection is blocked too — the full-screen TUI has mouse reporting enabled, so normal click-drag selection of the URL is swallowed by the app; can't select + ⌘C.

Net effect: the URL is visible on screen but unfollowable. The TUI /login is a dead end.

What Should Happen?

• The login URL should auto-open via open / $BROWSER (it works when invoked manually).
• Failing that, c should reliably copy the URL to the system clipboard.
• With mouse reporting on, there should be a dependable copy affordance so the URL can be retrieved.

Steps to Reproduce

1. Trigger the /login screen in the TUI on macOS (e.g. after an auth/token issue).
2. Observe the URL does not auto-open a browser.
3. Press c — nothing lands on the clipboard.
4. Try to click-drag-select the URL — the TUI's mouse capture prevents selection.
5. Login cannot be completed without leaving the TUI.

Workaround

Authenticate from a plain shell instead of the TUI — there the URL prints as ordinary selectable text and auto-opens via open:

claude auth logout
claude auth login --claudeai
claude auth status

Note

Filed as a focused follow-up split out from #72006 (which was closed as a duplicate of #71757 for the separate token-refresh/auth-wipe bug). This report is specifically about the unusable /login URL UX in the TUI.