Split CI: tests on hera, deploy on oci

- test.yml: unit + e2e + build on 'test' runner (hera)
  - Vitest results + Cypress videos/screenshots as artifacts
  - Auto starts/stops backend + frontend for E2E
- preview.yml: test on hera → deploy on oci (sequential)
- deploy.yml: test on hera → deploy-prod on oci

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

.gitea/workflows/preview.yml

@@ -4,18 +4,22 @@ on:
     types: [opened, synchronize, reopened, closed]
 
 jobs:
+  test:
+    if: github.event.action != 'closed'
+    runs-on: test
+    steps:
+      - uses: actions/checkout@v4
+      - name: Unit tests
+        run: cd frontend && npm ci && npx vitest run
+
   deploy-preview:
     if: github.event.action != 'closed'
+    needs: test
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
-
-      - name: Unit tests
-        run: cd frontend && npm ci && npm run test:unit
-
       - name: Deploy Preview
         run: python3 scripts/deploy-preview.py deploy ${{ github.event.pull_request.number }}
-
       - name: Comment PR
         env:
           GIT_TOKEN: ${{ secrets.GIT_TOKEN }}
@@ -32,10 +36,8 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
-
       - name: Teardown
         run: python3 scripts/deploy-preview.py teardown ${{ github.event.pull_request.number }}
-
       - name: Comment PR
         env:
           GIT_TOKEN: ${{ secrets.GIT_TOKEN }}