test(e2e): smoke tests that drive the real binary

The brief asked for these under Definition of done and they were never
written. 610 Go tests, none of which opens a browser.

Six flows: create the first account and sign in, quick add and tick a
task off, click every link in the sidebar, open a task and edit it, walk
every settings tab, and check that the manifest's icons and the service
worker can actually be fetched. Every assertion is on rendered content
rather than on a URL — the binary serves the SPA shell for anything it
does not recognise, so toHaveURL passes on precisely the bug this exists
to catch.

The suite builds the frontend, copies it into cmd/verdande/webbuild and
starts the real binary, every run. Merely starting the server would test
whatever frontend was copied there last, which during development is
nearly always the wrong one, and a green report on code that is not
running is worse than no report.

Chromium only. A smoke test catches a build that does not work at all;
running it in three engines finds the same breakage three times.

They found four bugs the first time they ran, fixed in the commits before
this one: concurrent writes returning SQLITE_BUSY, a completed task
keeping its row, the same task landing in the list twice, and a database
failure presenting as everybody being logged out.

Co-Authored-By: Claude Opus 5 <[email protected]>

.github/workflows/ci.yml

@@ -45,6 +45,49 @@ jobs:
       - name: Build
         run: CGO_ENABLED=0 go build ./...
 
+  e2e:
+    name: End-to-end
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-go@v5
+        with:
+          go-version: "1.26"
+          cache: true
+
+      - uses: actions/setup-node@v4
+        with:
+          node-version: "22"
+          cache: npm
+          cache-dependency-path: web/package-lock.json
+
+      - name: Install
+        working-directory: web
+        run: npm ci --no-audit --no-fund
+
+      # Chromium only. A smoke test exists to catch a build that does not work at
+      # all; running it three times in three engines finds the same breakage three
+      # times and costs three times as much.
+      - name: Install Chromium
+        working-directory: web
+        run: npx playwright install --with-deps chromium
+
+      # The suite builds the frontend, embeds it and starts the real binary — see
+      # playwright.config.js. There is nothing to build here first.
+      - name: Test
+        working-directory: web
+        run: npm run test:e2e
+
+      - if: failure()
+        uses: actions/upload-artifact@v4
+        with:
+          name: playwright-report
+          path: |
+            web/test-results/
+            web/playwright-report/
+          retention-days: 7
+
   docker:
     name: Docker image builds
     runs-on: ubuntu-latest