ci: fix E2E postgres-test collision and smoke @playwright/test resolution

E2E: test-server.mjs always spins up its own postgres-test container
and publishes port 5432 on the docker host — colliding with Gitea's
core postgres on the QNAP runner. Add PLAYWRIGHT_USE_EXTERNAL_DB
opt-in so CI can reuse the e2epg job-service container (which
test-server still pushes+seeds into). Set the flag in the E2E job.

docker-deploy smoke: install @playwright/test locally (no -g, no
--save) so the CJS require() in apps/web/playwright.ci.config.ts
resolves it by walking up from the config directory. Global npm
install lands in a hostedtoolcache path Node does not search.

.github/workflows/ci.yml

@@ -323,6 +323,11 @@ jobs:
       # ${PGADMIN_PASSWORD:?} check fires and aborts the compose call.
       # Provide a dummy value so parsing succeeds — pgadmin is never started.
       PGADMIN_PASSWORD: ci-unused
+      # Tell test-server.mjs not to spin up its own postgres-test container
+      # — the e2epg job service is already running and reachable. Without
+      # this, test-server tries to publish 5432 on the QNAP host, which
+      # collides with Gitea's core postgres.
+      PLAYWRIGHT_USE_EXTERNAL_DB: "true"
       NEXTAUTH_URL: ${{ env.CI_AUTH_URL }}
       AUTH_URL: ${{ env.CI_AUTH_URL }}
       NEXTAUTH_SECRET: ${{ env.CI_AUTH_SECRET }}
@@ -491,9 +496,13 @@ jobs:
           node-version: "20"
 
       - name: Install Playwright and Chromium
+        # Install locally (not -g) so the CJS require() in playwright.ci.config.ts
+        # resolves @playwright/test by walking up from apps/web/. A global
+        # install puts it in /opt/hostedtoolcache/.../lib/node_modules which
+        # Node's resolver doesn't check.
         run: |
-          npm install -g @playwright/test@1.49
-          playwright install chromium --with-deps
+          npm install --no-save --no-package-lock @playwright/test@1.49
+          npx playwright install chromium --with-deps
 
       - name: Run smoke tests
         env: