feat(test): implementazione infrastruttura completa (Unit, Integration, E2E) con Vitest e Playwright

- Introduce Vitest per Unit e Integration Test.
- Introduce Playwright per End-to-End Test.
- Aggiuge documentazione dettagliata in tests/README.md.
- Aggiorna .gitignore per escludere i report di coverage

package.json

@@ -8,7 +8,13 @@
     "build": "vite build",
     "preview": "node server.js",
     "start": "node server.js",
-    "serve": "vite build && node server.js"
+    "serve": "vite build && node server.js",
+    "test": "vitest",
+    "test:unit": "vitest run tests/unit tests/integration",
+    "test:ui": "vitest --ui",
+    "test:e2e": "playwright test",
+    "test:e2e:ui": "playwright test --ui",
+    "test:e2e:codegen": "playwright codegen"
   },
   "dependencies": {
     "express": "^5.2.1",
@@ -18,9 +24,14 @@
     "ws": "^8.19.0"
   },
   "devDependencies": {
+    "@playwright/test": "^1.58.2",
+    "@types/node": "^25.2.3",
     "@vitejs/plugin-vue": "^4.1.0",
+    "@vitest/ui": "^4.0.18",
     "concurrently": "^9.2.1",
+    "jsdom": "^28.0.0",
     "vite": "^4.3.9",
-    "vite-plugin-pwa": "^0.16.0"
+    "vite-plugin-pwa": "^0.16.0",
+    "vitest": "^4.0.18"
   }
 }