/resume defaults to showing all projects instead of current directory

Description

The /resume session picker now defaults to showing sessions from all projects instead of only the current directory.

Previously, /resume showed only sessions from the current directory by default — this behavior changed recently without a corresponding setting to control it.

Steps to reproduce

1. Navigate to any project directory
2. Run /resume
3. Session picker shows all sessions across all projects (e.g., ~/bin, ~/MyDocs/ResearchDocs, ~/Temp, etc.)

Expected behavior

/resume should default to showing sessions from the current directory only, as it did before.

Current workaround

Press Ctrl+A to toggle back to current directory view each time.

Feature request

Add a setting to control the default filter for /resume (e.g., resume.defaultScope: "current-directory" | "all").