feat(e2e): add Playwright E2E test suite for critical user journeys (GRO-306)

Implements the automated Playwright E2E suite as the pre-UAT gate following
the UAT failures identified in GRO-299. Creates 5 test files in apps/web/e2e/:

- portal-auth.spec.ts: verifies client portal auth (client name shown, not "Hi, Guest")
- portal-data.spec.ts: verifies portal sections render without auth gates
- admin-services.spec.ts: asserts no duplicate service names in admin/services and booking wizard
- admin-reports.spec.ts: verifies reports page shows non-zero data for last 60 days
- console-health.spec.ts: asserts no 404s for favicon/PWA assets and no JS exceptions

Also adds:
- apps/web/e2e/ with Playwright config targeting groombook.dev.farh.net
- Shared fixtures with storageState-based auth via dev login selector
- test:e2e npm script in apps/web/package.json
- web-e2e CI job targeting PRs (runs after deploy-dev)

Note: Tests 1 & 2 (portal auth/data) depend on GRO-300 being deployed.
Tests 3-5 run against current dev state.

Co-Authored-By: Paperclip <noreply@paperclip.ing>

apps/web/package.json

@@ -9,7 +9,8 @@
     "preview": "vite preview",
     "lint": "eslint src --ext .ts,.tsx",
     "typecheck": "tsc --noEmit",
-    "test": "vitest run"
+    "test": "vitest run",
+    "test:e2e": "playwright test -c e2e/playwright.config.ts"
   },
   "dependencies": {
     "@groombook/types": "workspace:*",
@@ -23,6 +24,7 @@
     "tailwindcss": "^4.2.2"
   },
   "devDependencies": {
+    "@playwright/test": "^1.50.1",
     "@testing-library/jest-dom": "^6.9.1",
     "@testing-library/react": "^16.3.2",
     "@testing-library/user-event": "^14.6.1",