Option+click expand all beach balls on large directories #14

When Option+clicking the root node to expand all, the app beach balls briefly before rendering. This is caused by SwiftUI expanding thousands of DisclosureGroups simultaneously.

Likely culprits are large directories like storage/ (890+ items) and tmp/ (1600+ items) in a production Rails app.

Possible mitigations:

• Add tmp/, storage/, node_modules/ to default ignore patterns (or recommend them)
• Progressive expansion (expand level by level with animation instead of all at once)
• Investigate if SwiftUI has a way to batch DisclosureGroup state changes