test(nightly): stabilize the exhaustive nightly suite (#345)

Triaged the nightly failures (all pre-existing, unrelated to the analytics
work) and fixed the ones with clear root causes:

- video-speed: a 1s tiny.mp4 sped up 2x rounds to ~0.75s, flaking the +/-25%
  duration assertion under heavy CI load. Use the 8s hero.mp4 (still 44.1kHz)
  so rounding is negligible. Verified locally.
- Extended Matrix + Coverage timeouts: full-matrix / coverage-instrumented runs
  starve the heavy media tests under 4 forks at the 30s default. Make maxForks
  env-overridable (VITEST_MAX_FORKS) and run those jobs with 2 forks + a 300s
  timeout so format-matrix conversions and qr-generate stop timing out.
- Device Matrix visual baselines: the update-visual-baselines workflow could
  not start the app ('failed to create database') because it never provisioned
  Postgres/Redis. Add the same services block the e2e jobs use.
- Docker E2E: a container pnpm install network blip exits 254. Add fetch
  retries + a longer network timeout (frozen-lockfile already passes locally).
- Cross-browser: the home page is the tool catalog now (no dropzone), and the
  tool routes moved to /<section>/<toolId>. Point the upload test at a real
  tool page and fix the stale single-segment routes (/resize -> /image/resize,
  etc.).

The flaky/timeout and cross-browser fixes can only be confirmed by the nightly
(they are load- and browser-specific); a fresh nightly run will verify.

.github/workflows/update-visual-baselines.yml

@@ -12,6 +12,32 @@ jobs:
     name: Regenerate linux visual baselines
     runs-on: ubuntu-latest
     timeout-minutes: 60
+    # The e2e webServer (playwright.config.ts) creates an isolated database via
+    # tests/e2e-pg-create-db.cjs, so it needs Postgres + Redis on localhost.
+    # Without these services the webServer fails with "failed to create database".
+    services:
+      postgres:
+        image: postgres:17-alpine
+        env:
+          POSTGRES_USER: snapotter
+          POSTGRES_PASSWORD: snapotter
+          POSTGRES_DB: snapotter
+        ports:
+          - 5432:5432
+        options: >-
+          --health-cmd "pg_isready -U snapotter"
+          --health-interval 5s
+          --health-timeout 3s
+          --health-retries 10
+      redis:
+        image: redis:8-alpine
+        ports:
+          - 6379:6379
+        options: >-
+          --health-cmd "redis-cli ping"
+          --health-interval 5s
+          --health-timeout 3s
+          --health-retries 10
     steps:
       - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
       - uses: ./.github/actions/setup