feat: Add Mem0 integration and collapsible project folders

[isasardar1-coder]

Summary

Type of Change

• Bug fix
• [✅] New feature
• [✅] Documentation
• Refactor
• Other

Validation

Checklist

• [✅] I ran relevant checks/tests locally.
• I updated docs if behavior or interfaces changed.
• I verified there are no unrelated changes in this PR.

[isasardar1-coder]

The backend suite is fixed and pushed to feature/mem0-and-sidebar.

I addressed the breakage by running the affected backend specs under Vitest’s Node runtime instead of the shared jsdom pipeline, then made the shared test setup safe for both environments in [tests/setup.ts]. I also updated the brittle Windows path assertions and [plugin-install.test.ts] and marked the backend-only specs explicitly with @vitest-environment node.

pnpm run test now passes fully: 53 files, 267 tests green. The fix is committed as 7c6bc00 (Fix backend tests under node runtime) and pushed to origin/feature/mem0-and-sidebar.