Stage 7: run the e2e suite in WebKit too (Safari-engine coverage)

Add a webkit project to the Playwright config so the hermetic mock-mode specs run
in both Chromium and WebKit, and install both browsers in CI. WebKit's Debian build
runs headless without extra host system libraries (verified locally: smoke + zoom
pass in webkit); the workflow comment records the one-time host install-deps fallback
if a runner ever lacks a library. Desktop WebKit does not reproduce iOS Safari's text
auto-inflation, so the app.css text-size-adjust guard stays outside e2e coverage.

.gitea/workflows/ui-test.yaml

@@ -1,8 +1,8 @@
 name: Tests · UI
 
 # Hermetic UI checks: type-check, Vitest unit tests, production build with a
-# bundle-size budget, and a Playwright smoke against the in-memory mock transport
-# (no backend/gateway/Postgres). The committed src/gen/ codegen is built, not
+# bundle-size budget, and a Playwright smoke (Chromium + WebKit) against the in-memory
+# mock transport (no backend/gateway/Postgres). The committed src/gen/ codegen is built, not
 # regenerated (the same model as the Go committed jet/fbs output).
 
 on:
@@ -51,12 +51,15 @@ jobs:
 
       # The Playwright system libraries are provisioned once on the runner host
       # (`sudo npx playwright@<version> install-deps chromium`), so the job needs no
-      # apt and no sudo: it only downloads the browser binary into the runner cache
-      # (persisted by the host executor) and runs the smoke. The timeouts guard
-      # against a future hang. Keep this in lockstep with @playwright/test in
-      # package.json — re-run install-deps on the host after a major bump.
-      - name: Install Playwright browser
-        run: pnpm exec playwright install chromium
+      # apt and no sudo: it only downloads the browser binaries into the runner cache
+      # (persisted by the host executor) and runs the suite. WebKit's Debian build
+      # bundles most of its own libraries and runs headless without extra host deps; if
+      # a runner ever lacks one, provision it once on the host with
+      # `sudo npx playwright install-deps webkit`. The timeouts guard against a future
+      # hang. Keep this in lockstep with @playwright/test in package.json — re-run
+      # install-deps on the host after a major bump.
+      - name: Install Playwright browsers
+        run: pnpm exec playwright install chromium webkit
         timeout-minutes: 5
 
       - name: E2E smoke (mock)

ui/playwright.config.ts

@@ -18,5 +18,12 @@ export default defineConfig({
     reuseExistingServer: !process.env.CI,
     timeout: 60_000,
   },
-  projects: [{ name: 'chromium', use: { ...devices['Desktop Chrome'] } }],
+  // Run the same hermetic specs in Chromium and WebKit (Safari's engine) so the UI is
+  // exercised in both rendering/JS engines. Note: desktop WebKit on Linux does not
+  // reproduce iOS Safari's text auto-inflation, so the `text-size-adjust` guard in
+  // app.css is not regression-covered here — but engine-level CSS/JS differences are.
+  projects: [
+    { name: 'chromium', use: { ...devices['Desktop Chrome'] } },
+    { name: 'webkit', use: { ...devices['Desktop Safari'] } },
+  ],
 });