Status bar shows merged/closed PR instead of hiding it

Description

The Claude Code status bar at the bottom of the terminal displays a PR number associated with the current branch (e.g., PR #35). However, it shows already merged/closed PRs, which is confusing and not useful.

Steps to Reproduce

1. Have a branch (e.g., develop) that was previously used to create a PR
2. The PR was merged and closed
3. Continue working on the same branch with new commits
4. Claude Code status bar still shows the old merged PR number

Expected Behavior

• If there's no open PR for the current branch, don't show any PR indicator in the status bar
• Or at minimum, indicate the PR status (e.g., PR #35 (merged)) so it's clear it's not an active PR

Actual Behavior

The status bar shows PR #35 with no indication that it's already merged, making it look like there's an active PR when there isn't one.

Environment

• macOS (Darwin 24.6.0)
• Claude Code CLI