Added optionnal online storage and cross-client sync

package.json

@@ -12,11 +12,14 @@
     "test:watch": "vitest",
     "check": "svelte-check --tsconfig ./jsconfig.json",
     "test:e2e": "playwright test",
-    "validate:all": "npm run validate && npm run test:e2e"
+    "validate:all": "npm run validate && npm run test:e2e",
+    "sync:server": "node server/index.js",
+    "test:sync": "vitest run src/lib/sync server"
   },
   "devDependencies": {
     "@playwright/test": "^1.64.0",
     "@sveltejs/vite-plugin-svelte": "^7.1.2",
+    "@types/qrcode": "^1.5.6",
     "@vite-pwa/assets-generator": "^1.0.2",
     "fake-indexeddb": "^6.2.5",
     "svelte": "^5.56.4",
@@ -26,6 +29,8 @@
     "vitest": "^5.0.0"
   },
   "dependencies": {
-    "dexie": "^4.4.4"
+    "@hpke/core": "^1.9.0",
+    "dexie": "^4.4.4",
+    "qrcode": "^1.5.4"
   }
 }