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/e2e/playwright.config.ts

@@ -0,0 +1,34 @@
+import { defineConfig, devices } from "@playwright/test";
+
+/**
+ * Playwright configuration for GroomBook Web E2E tests.
+ *
+ * Targets the deployed dev environment at groombook.dev.farh.net.
+ * Uses the dev login selector (/login) for authentication — no hardcoded credentials.
+ *
+ * Run locally:
+ *   pnpm --filter @groombook/web-e2e test
+ *
+ * CI: Runs on every PR targeting main, blocking merge on failure.
+ */
+export default defineConfig({
+  testDir: "./tests",
+  timeout: 30_000,
+  retries: process.env.CI ? 2 : 0,
+  workers: process.env.CI ? 1 : undefined,
+  reporter: process.env.CI ? "github" : "list",
+
+  use: {
+    baseURL: "https://groombook.dev.farh.net",
+    trace: "on-first-retry",
+    screenshot: "only-on-failure",
+    serviceWorkers: "block",
+  },
+
+  projects: [
+    {
+      name: "chromium",
+      use: { ...devices["Desktop Chrome"] },
+    },
+  ],
+});