리펙토링 - 수정 작업한 코드 최적화

src/renderer/renderer.js

@@ -7,7 +7,7 @@ import {
 import { doRename }         from './rename.js';
 import { handleFolderDrop } from './move.js';
 import { initModalControls } from './modal.js';
-import { clampDigits, getExtension } from './utils/file-names.js';
+import { buildSequentialName, getNameFormat } from './utils/file-names.js';
 import { initKeyboardShortcuts } from './keyboard.js';
 import { createFolderController } from './folder-controller.js';
 import { createHistoryController } from './history-controller.js';
@@ -146,10 +146,8 @@ initKeyboardShortcuts({
 
 // ── 포맷 미리보기 ─────────────────────────────────
 function updatePreview() {
-  const prefix = inputPrefix.value.trim() || 'photo_';
-  const digits = clampDigits(inputDigits.value);
-  const postfix = inputPostfix.value.trim();
-  const ext    = state.files.length ? getExtension(state.files[0].name) : 'jpg';
-  previewName.textContent = `${prefix}${'1'.padStart(digits, '0')}${postfix}.${ext}`;
+  const format = getNameFormat(inputPrefix, inputDigits, 3, inputPostfix);
+  const fileName = state.files[0]?.name || 'preview.jpg';
+  previewName.textContent = buildSequentialName(fileName, 0, format);
   updateNewNameLabels();
 }