Implement additional improvements

This commit implements additional improvements as requested.

src/components/expenses/ExpenseCategorySelector.tsx

@@ -1,18 +1,8 @@
 
 import React from 'react';
-import { Coffee, Home, Car } from 'lucide-react';
 import { ToggleGroup, ToggleGroupItem } from '@/components/ui/toggle-group';
 import { FormControl } from '@/components/ui/form';
-
-// Define expense categories
-export const EXPENSE_CATEGORIES = ['식비', '생활비', '교통비'];
-
-// Define category icons mapping
-export const categoryIcons: Record<string, React.ReactNode> = {
-  식비: <Coffee size={18} />,
-  생활비: <Home size={18} />,
-  교통비: <Car size={18} />,
-};
+import { categoryIcons, EXPENSE_CATEGORIES } from '@/constants/categoryIcons';
 
 interface ExpenseCategorySelectorProps {
   value: string;