phase 2: ui testing infrastructure

Vitest + @testing-library/jest-dom matchers wired through tests/setup.ts.
Playwright with four projects: chromium-desktop, webkit-desktop,
chromium-mobile-iphone-13, chromium-mobile-pixel-5; traces and
screenshots retained on failure.

.gitea/workflows/ui-test.yaml runs Tier 1 on every push and pull
request: monorepo Go service tests (backend with -p 1 to dodge
testcontainer contention; gateway, game, every pkg/<name> module),
pnpm install --frozen-lockfile, playwright install --with-deps,
pnpm test, pnpm exec playwright test. Uploads playwright-report
and test-results on failure. Integration suite stays gated behind
make -C integration integration; deprecated client/ excluded.

.gitea/workflows/ui-release.yaml mirrors Tier 1 on v* tag push and
keeps commented placeholders for visual regression (Phase 33) and
macOS iOS smoke (Phase 32).

ui/docs/testing.md documents both tiers and the local invocations
that mirror what CI runs. ui/PLAN.md Phase 2 marked done; Phase 3
gains a bullet to extend the go test command with ./ui/core/...;
Phase 36 has the renamed release workflow path.

tools/local-ci/ ships a self-contained docker-compose for verifying
workflows against a local Gitea + arm64 act_runner before pushing
to a real instance.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

tools/local-ci/config.yaml

@@ -0,0 +1,35 @@
+# act_runner configuration.
+#
+# The `ubuntu-latest` label is mapped to catthehacker/ubuntu:act-latest,
+# which is multi-arch — Docker on Apple Silicon pulls the arm64 variant
+# and runs it natively (no QEMU). The same image is what `act` uses
+# locally, so workflows behave the same.
+
+log:
+  level: info
+
+runner:
+  file: /data/.runner
+  capacity: 1
+  fetch_timeout: 5s
+  fetch_interval: 2s
+  labels:
+    - "ubuntu-latest:docker://catthehacker/ubuntu:act-latest"
+
+cache:
+  enabled: true
+  dir: /data/cache
+
+container:
+  # Spawned workflow containers join the same network as Gitea so
+  # actions/checkout and other steps can reach the server at
+  # http://gitea:3000.
+  network: galaxy-local-gitea-net
+  privileged: false
+  options: ""
+  workdir_parent: ""
+  valid_volumes: []
+  force_pull: false
+
+host:
+  workdir_parent: ""