Filter /resume history by current project directory

Problem

When using /resume, it shows all recent conversations across every project globally. If I work on multiple projects throughout the day, the resume list becomes cluttered with conversations from unrelated projects, making it harder to find the one I want to continue.

Expected Behavior

/resume should filter conversations by the current working directory (project), showing only conversations that were started in the same project. The conversation data is already organized by project path internally (~/.claude/projects/<path-based-dir>/), so the filtering info is already available.

Suggested Approach

• Default /resume to show only conversations from the current project
• Optionally, add a flag like /resume --all to show the global list when needed

This would make /resume much more useful in multi-project workflows.