chore: migrate to @vigdorov/* shared configs (eslint, prettier, typescript, vite)

Replace project-local ESLint, Prettier, TypeScript, and Vite configs
with shared packages from dev-configs monorepo.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

frontend/tsconfig.node.json

@@ -1,25 +1,17 @@
 {
+  "extends": "@vigdorov/typescript-config/base",
   "compilerOptions": {
     "tsBuildInfoFile": "./node_modules/.tmp/tsconfig.node.tsbuildinfo",
     "target": "ES2023",
     "lib": ["ES2023"],
-    "module": "ESNext",
     "types": ["node"],
-    "skipLibCheck": true,
-
-    /* Bundler mode */
-    "moduleResolution": "bundler",
     "allowImportingTsExtensions": true,
     "verbatimModuleSyntax": true,
     "moduleDetection": "force",
     "noEmit": true,
-
-    /* Linting */
-    "strict": true,
     "noUnusedLocals": true,
     "noUnusedParameters": true,
     "erasableSyntaxOnly": true,
-    "noFallthroughCasesInSwitch": true,
     "noUncheckedSideEffectImports": true
   },
   "include": ["vite.config.ts"]