feat: add unit tests

apps/main/package.json

@@ -8,6 +8,7 @@
         "dev": "vite dev",
         "build": "pnpm cp && vite build",
         "serve": "serve build --listen 5173",
+        "test:unit": "jest",
         "test:e2e": "playwright test",
         "clean": "rm -rf .turbo .svelte-kit build node_modules vite.config.ts.timestamp-*",
         "lint": "eslint ."
@@ -23,6 +24,7 @@
         "@playwright/test": "^1.36.2",
         "@sveltejs/adapter-static": "^2.0.2",
         "@sveltejs/kit": "^1.22.1",
+        "@types/jest": "^29.5.3",
         "@typescript-eslint/eslint-plugin": "^5.61.0",
         "@typescript-eslint/parser": "^5.61.0",
         "autoprefixer": "^10.4.14",
@@ -31,6 +33,7 @@
         "eslint-plugin-import": "^2.27.5",
         "eslint-plugin-simple-import-sort": "^10.0.0",
         "eslint-plugin-svelte": "^2.32.2",
+        "jest": "^29.6.2",
         "postcss": "^8.4.25",
         "prettier-plugin-svelte": "^2.10.1",
         "prettier-plugin-tailwindcss": "^0.3.0",
@@ -39,6 +42,7 @@
         "svelte": "^4.0.5",
         "svelte-check": "^3.4.5",
         "tailwindcss": "^3.3.2",
+        "ts-jest": "^29.1.1",
         "tslib": "^2.6.0",
         "typescript": "^5.1.6",
         "vite": "^4.4.2"