Problem

Operators need a real workspace tree so sessions can browse and attach repository context without leaving the app.

Scope

• Add tree navigation, filtering, fuzzy search, and open-file behavior
• Respect .gitignore and app-specific ignore rules
• Define performance expectations for medium and large repos

Out of scope

• Re-creating basic .gitignore files that already exist in the repo
• Monaco editor implementation details beyond tree-to-open-file behavior

Implementation notes

• Keep the repository tree tightly integrated with attachments and file viewing
• Make repo browsing an operator feature, not just a coding-only affordance
• Preserve desktop-first usability

Definition of Done

• The issue explicitly defines tree behavior, ignore behavior, and file-opening expectations
• Performance expectations are concrete enough for later testing

Verification

• Review the issue against the feature spec operator flow

Dependencies

• Parent epic: [Epic] Replace the static prototype with a real desktop workbench #13