fix(01-02): resolve TypeScript build errors for production build

- Fix palette.test.ts: use type-only import for CategoryType (verbatimModuleSyntax)
- Fix vite.config.ts: import defineConfig from vitest/config for test property support
- Fix tsconfig.node.json: add vitest/globals to types array
- Fix AvailableBalance.tsx: split typed array and filter to preserve CategoryType literal

frontend/src/components/AvailableBalance.tsx

@@ -16,14 +16,15 @@ export function AvailableBalance({ budget }: Props) {
 
   const available = totals.available
 
-  const data: Array<{ name: string; value: number; categoryType: CategoryType }> = [
+  const allData: Array<{ name: string; value: number; categoryType: CategoryType }> = [
     { name: t('dashboard.remaining'), value: Math.max(0, available), categoryType: 'carryover' },
     { name: t('dashboard.bills'), value: totals.bills_actual, categoryType: 'bill' },
     { name: t('dashboard.expenses'), value: totals.expenses_actual, categoryType: 'variable_expense' },
     { name: t('dashboard.debts'), value: totals.debts_actual, categoryType: 'debt' },
     { name: t('dashboard.savings'), value: totals.savings_actual, categoryType: 'saving' },
     { name: t('dashboard.investments'), value: totals.investments_actual, categoryType: 'investment' },
-  ].filter((d) => d.value > 0)
+  ]
+  const data = allData.filter((d) => d.value > 0)
 
   return (
     <Card>

frontend/src/lib/palette.test.ts

@@ -1,7 +1,7 @@
 import { describe, it, expect } from 'vitest'
 import {
   palette,
-  CategoryType,
+  type CategoryType,
   headerGradient,
   overviewHeaderGradient,
   amountColorClass,

frontend/tsconfig.node.json

@@ -4,7 +4,7 @@
     "target": "ES2023",
     "lib": ["ES2023"],
     "module": "ESNext",
-    "types": ["node"],
+    "types": ["node", "vitest/globals"],
     "skipLibCheck": true,
 
     /* Bundler mode */

frontend/vite.config.ts

@@ -1,5 +1,4 @@
-/// <reference types="vitest" />
-import { defineConfig } from 'vite'
+import { defineConfig } from 'vitest/config'
 import react from '@vitejs/plugin-react'
 import tailwindcss from '@tailwindcss/vite'
 import path from 'path'