1.**backend-tests**: `astral-sh/setup-uv@v6.8.0` requires Node.js 20+ but the act runner has Node.js 18. The `File` global doesn't exist in Node 18, causing a ReferenceError. Fix: install uv directly via curl instead of using the GitHub Action.
2.**e2e-tests**: Port 8000 is already allocated on the runner host. The docker-compose.test.yml binds test-api to host port 8000 which conflicts with whatever else runs on the CI machine. Fix: use port 8100 for the test API container.
## Checklist
- [x] Replace `astral-sh/setup-uv` action with direct curl install of uv + `uv python install 3.14`
- [x] Change e2e test API host port from 8000 to 8100 in docker-compose.test.yml
- [x] Update global-setup.ts to use port 8100
- [x] Verify no other references to the test API port