Refactor expense form and categories

-   Rename "지출 추가" to "지출 입력" in the add expense dialog.
-   Rename "교통비" to "교통" in categories and ensure all 4 icons are displayed on a single line.

src/components/AddTransactionButton.tsx

@@ -1,4 +1,3 @@
-
 import React, { useState, useEffect } from 'react';
 import { PlusIcon } from 'lucide-react';
 import { Dialog, DialogContent, DialogHeader, DialogTitle } from './ui/dialog';
@@ -155,7 +154,7 @@ const AddTransactionButton = () => {
       }}>
         <DialogContent className="w-[90%] max-w-sm mx-auto">
           <DialogHeader>
-            <DialogTitle>지출 추가</DialogTitle>
+            <DialogTitle>지출 입력</DialogTitle>
           </DialogHeader>
           <ExpenseForm 
             onSubmit={onSubmit}