feat(store): Clock trait for DST

Lewis: May this revision serve well! <lu5a@proton.me>

frontend/package.json

@@ -7,8 +7,11 @@
     "dev": "vite",
     "build": "vite build",
     "preview": "vite preview",
+    "check": "svelte-check --tsconfig ./tsconfig.json",
     "test": "vitest",
     "test:run": "vitest run",
+    "test:watch": "vitest",
+    "test:ui": "vitest --ui",
     "test:coverage": "vitest run --coverage"
   },
   "dependencies": {
@@ -26,6 +29,8 @@
     "@testing-library/jest-dom": "^6.9.1",
     "@testing-library/svelte": "^5.3.1",
     "@testing-library/user-event": "^14.6.1",
+    "@vitest/coverage-v8": "4.1.4",
+    "@vitest/ui": "4.1.4",
     "jsdom": "^25.0.1",
     "svelte": "^5.46.1",
     "svelte-check": "^4.3.5",