Fix CI: remove unused aliases, run mix format, install root yarn deps

- Remove unused aliases that caused warnings-as-errors in EX_CHECK mode
- Run mix format to fix formatter check
- Add root-level yarn install to CI for prettier (used by mix check)
- All 1007 tests pass, zero warnings

.gitea/workflows/ci.yml

@@ -41,6 +41,7 @@ jobs:
       - name: Install deps
         run: |
           docker compose exec -T phx mix deps.get
+          docker compose exec -T phx yarn install
           docker compose exec -T phx sh -c "cd assets && yarn install"
 
       - name: Create and Migrate database