chore(ci): capture server stderr + dump on failure

Backgrounding 'node .output/server/index.mjs &' swallowed startup
crashes — failures presented as a useless 30s 'Wait for server'
timeout. Pipe stderr to a log file and cat it on failure so the
next crash is one click away.

.forgejo/workflows/test.yml

@@ -44,11 +44,14 @@ jobs:
       - run: npx playwright install --with-deps chromium
       - run: npm run build
       - name: Start server
-        run: node .output/server/index.mjs &
+        run: node .output/server/index.mjs > /tmp/server.log 2>&1 &
         env:
           PORT: 3000
       - name: Wait for server
         run: timeout 30 sh -c 'until curl -sf http://localhost:3000; do sleep 1; done'
+      - name: Server log on failure
+        if: failure()
+        run: cat /tmp/server.log || true
       - run: npx playwright test --ignore-snapshots
       - uses: actions/upload-artifact@v4
         if: failure()
@@ -98,11 +101,14 @@ jobs:
       - run: npx playwright install --with-deps chromium
       - run: npm run build
       - name: Start server
-        run: node .output/server/index.mjs &
+        run: node .output/server/index.mjs > /tmp/server.log 2>&1 &
         env:
           PORT: 3000
       - name: Wait for server
         run: timeout 30 sh -c 'until curl -sf http://localhost:3000; do sleep 1; done'
+      - name: Server log on failure
+        if: failure()
+        run: cat /tmp/server.log || true
       - run: npx playwright test e2e/visual/
       - uses: actions/upload-artifact@v4
         if: failure()