refactor: migrate to eslint flat config and format codebase with prettier

- Remove legacy .eslintrc.cjs and .eslintignore
- Add eslint.config.js with flat config, security rules (no-eval, no-implied-eval, no-new-func, no-script-url)
- Add .prettierrc and .prettierignore
- Format entire codebase with prettier

vite.config.ts

@@ -1,9 +1,15 @@
-import { defineConfig } from 'vite'
-import react from '@vitejs/plugin-react'
+import { defineConfig } from 'vite';
+import react from '@vitejs/plugin-react';
+import path from 'path';
 
 // https://vitejs.dev/config/
 export default defineConfig({
   plugins: [react()],
+  resolve: {
+    alias: {
+      '@': path.resolve(__dirname, 'src'),
+    },
+  },
   // Base path - use '/' for standalone Docker deployment
   // Change to '/cabinet/' if serving from a sub-path
   base: '/',
@@ -23,4 +29,4 @@ export default defineConfig({
     outDir: 'dist',
     sourcemap: false,
   },
-})
+});