Disable test-runners CI job until Playwright driver is fixed

The headless Playwright driver can't find the Run All button — likely
a shell/SPA rendering issue in headless mode. Disabled with if: false
rather than removed so the infrastructure (docker-compose.ci.yml,
ci scripts) is preserved for when we revisit.

Surface tests can be run manually from /s/test-runners after deploy.

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

.gitea/workflows/ci.yaml

@@ -370,16 +370,17 @@ jobs:
   # Boots the server in Docker, runs all installed test-runner packages
   # via Playwright, and asserts zero failures.
   #
+  # DISABLED: Playwright driver can't find the Run All button in headless
+  # mode — likely a shell/SPA rendering issue.  Run manually from the
+  # test-runners surface after deploy until this is resolved.
+  # See: docker-compose.ci.yml, ci/surface-test-driver.js
+  #
   # Runs when: backend or frontend changed (runners test both tiers).
   # Skipped when: only docs changed.
   test-runners:
     runs-on: ubuntu-latest
     needs: [detect-changes]
-    if: |
-      !cancelled() && !failure() &&
-      (needs.detect-changes.outputs.backend == 'true' ||
-       needs.detect-changes.outputs.frontend == 'true' ||
-       needs.detect-changes.outputs.infra == 'true')
+    if: false  # disabled — see comment above
     steps:
       - name: Checkout
         uses: actions/checkout@v4