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/api-base.js

@@ -148,5 +148,88 @@
     return response.json();
   };
 
+  // ==================== 공통 유틸리티 ====================
+
+  /**
+   * Toast 알림 표시
+   */
+  window.showToast = function(message, type, duration) {
+    type = type || 'info';
+    duration = duration || 3000;
+
+    var container = document.getElementById('toastContainer');
+    if (!container) {
+      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')) {
+      var style = document.createElement('style');
+      style.id = 'toastStyles';
+      style.textContent =
+        '.toast{display:flex;align-items:center;gap:12px;padding:12px 20px;background:#fff;border-radius:8px;box-shadow:0 4px 12px rgba(0,0,0,.15);opacity:0;transform:translateX(100px);transition:all .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);
+    }
+
+    var iconMap = { success: '\u2705', error: '\u274C', warning: '\u26A0\uFE0F', info: '\u2139\uFE0F' };
+    var toast = document.createElement('div');
+    toast.className = 'toast toast-' + type;
+    toast.innerHTML = '<span class="toast-icon">' + (iconMap[type] || '\u2139\uFE0F') + '</span><span class="toast-message">' + message + '</span>';
+    container.appendChild(toast);
+
+    setTimeout(function() { toast.classList.add('show'); }, 10);
+    setTimeout(function() {
+      toast.classList.remove('show');
+      setTimeout(function() { toast.remove(); }, 300);
+    }, duration);
+  };
+
+  /**
+   * 날짜를 YYYY-MM-DD 형식으로 변환
+   */
+  window.formatDate = function(dateString) {
+    if (!dateString) return '';
+    if (/^\d{4}-\d{2}-\d{2}$/.test(dateString)) return dateString;
+    var d = new Date(dateString);
+    if (isNaN(d.getTime())) return '';
+    var y = d.getFullYear();
+    var m = String(d.getMonth() + 1).padStart(2, '0');
+    var day = String(d.getDate()).padStart(2, '0');
+    return y + '-' + m + '-' + day;
+  };
+
+  /**
+   * apiCall이 로드될 때까지 대기
+   */
+  window.waitForApi = function(timeout) {
+    timeout = timeout || 5000;
+    return new Promise(function(resolve, reject) {
+      if (window.apiCall) return resolve();
+      var elapsed = 0;
+      var iv = setInterval(function() {
+        elapsed += 50;
+        if (window.apiCall) { clearInterval(iv); resolve(); }
+        else if (elapsed >= timeout) { clearInterval(iv); reject(new Error('apiCall timeout')); }
+      }, 50);
+    });
+  };
+
+  /**
+   * UUID v4 생성
+   */
+  window.generateUUID = function() {
+    return 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'.replace(/[xy]/g, function(c) {
+      var r = Math.random() * 16 | 0;
+      var v = c === 'x' ? r : (r & 0x3 | 0x8);
+      return v.toString(16);
+    });
+  };
+
   console.log('API 설정 완료:', window.API_BASE_URL);
 })();