feat: add Vitest and Playwright testing frameworks

Set up Vitest for unit/integration tests and Playwright for E2E tests; add configs, tests, and documentation

Co-authored-by: Moheeb Zara <1184415+virgilvox@users.noreply.github.com>

package.json

@@ -6,7 +6,11 @@
     "dev": "next dev",
     "build": "next build",
     "start": "next start",
-    "lint": "eslint ."
+    "lint": "eslint .",
+    "test": "vitest",
+    "test:ui": "vitest --ui",
+    "test:e2e": "playwright test",
+    "test:e2e:ui": "playwright test --ui"
   },
   "dependencies": {
     "@hookform/resolvers": "^3.9.1",
@@ -62,14 +66,21 @@
     "@supabase/supabase-js": "^2.49.4"
   },
   "devDependencies": {
+    "@playwright/test": "^1.40.0",
     "@tailwindcss/postcss": "^4.2.0",
+    "@testing-library/jest-dom": "^6.1.5",
+    "@testing-library/react": "^14.1.2",
     "@types/node": "^22",
     "@types/react": "19.2.14",
     "@types/react-dom": "19.2.3",
+    "@vitejs/plugin-react": "^4.2.1",
+    "@vitest/ui": "^1.0.4",
+    "jsdom": "^23.0.1",
     "postcss": "^8.5",
     "shadcn": "^4.0.0",
     "tailwindcss": "^4.2.0",
     "tw-animate-css": "1.3.3",
-    "typescript": "5.7.3"
+    "typescript": "5.7.3",
+    "vitest": "^1.0.4"
   }
 }