refactor: 프론트엔드 유틸리티 함수 통합 (showToast, waitForApi, generateUUID)

- api-base.js에 4개 전역 유틸리티 추가 (showToast, formatDate, waitForApi, generateUUID)
- 24개 파일에서 중복 정의 제거 (-932줄)
- showToast: 18곳 중복 → 1곳 통합 (자동 컨테이너/스타일 생성)
- waitForApi/waitForApiConfig/waitForApiCall: 5곳 → 1곳 통합
- generateUUID: tbm.js 중복 제거
- tbm/utils.js, workplace-management/utils.js: window 재정의 제거

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

system1-factory/web/js/safety-training-conduct.js

@@ -8,85 +8,7 @@ let isDrawing = false;
 let hasSignature = false;
 let savedSignatures = []; // 저장된 서명 목록
 
-// ==================== Toast 알림 ====================
-
-function showToast(message, type = 'info', duration = 3000) {
-  const toastContainer = document.getElementById('toastContainer') || createToastContainer();
-
-  const toast = document.createElement('div');
-  toast.className = `toast toast-${type}`;
-
-  const iconMap = {
-    success: '✅',
-    error: '❌',
-    warning: '⚠️',
-    info: 'ℹ️'
-  };
-
-  toast.innerHTML = `
-    <span class="toast-icon">${iconMap[type] || 'ℹ️'}</span>
-    <span class="toast-message">${message}</span>
-  `;
-
-  toastContainer.appendChild(toast);
-
-  setTimeout(() => toast.classList.add('show'), 10);
-
-  setTimeout(() => {
-    toast.classList.remove('show');
-    setTimeout(() => toast.remove(), 300);
-  }, duration);
-}
-
-function createToastContainer() {
-  const container = document.createElement('div');
-  container.id = 'toastContainer';
-  container.style.cssText = `
-    position: fixed;
-    top: 20px;
-    right: 20px;
-    z-index: 9999;
-    display: flex;
-    flex-direction: column;
-    gap: 10px;
-  `;
-
-  document.body.appendChild(container);
-
-  if (!document.getElementById('toastStyles')) {
-    const style = document.createElement('style');
-    style.id = 'toastStyles';
-    style.textContent = `
-      .toast {
-        display: flex;
-        align-items: center;
-        gap: 12px;
-        padding: 12px 20px;
-        background: white;
-        border-radius: 8px;
-        box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
-        opacity: 0;
-        transform: translateX(100px);
-        transition: all 0.3s ease;
-        min-width: 250px;
-        max-width: 400px;
-      }
-      .toast.show {
-        opacity: 1;
-        transform: translateX(0);
-      }
-      .toast-success { border-left: 4px solid #10b981; }
-      .toast-error { border-left: 4px solid #ef4444; }
-      .toast-warning { border-left: 4px solid #f59e0b; }
-      .toast-info { border-left: 4px solid #3b82f6; }
-      .toast-icon { font-size: 20px; }
-      .toast-message { font-size: 14px; color: #374151; }
-    `;
-    document.head.appendChild(style);
-  }
-
-  return container;
-}
+// showToast → api-base.js 전역 사용
 
 // ==================== 초기화 ====================
 
@@ -544,7 +466,6 @@ function goBack() {
 }
 
 // 전역 함수로 노출
-window.showToast = showToast;
 window.clearSignature = clearSignature;
 window.saveSignature = saveSignature;
 window.deleteSignature = deleteSignature;