merge: 合并开发分支 Branch_master 到 master，同步所有功能迭代

index.html

@@ -19,6 +19,7 @@
                 <button class="toolbar-btn-icon" id="redoBtn" title="重做 (Ctrl+Y)">↪</button>
             </div>
             <div class="toolbar-divider-v divider-right"></div>
+            <button class="btn" id="layersBtn">图层</button>
             <button class="btn btn-primary" id="saveBtn">保存/预览</button>
         </div>
 
@@ -117,6 +118,19 @@
         </div>
 
 
+        <!-- 图层面板 -->
+        <div class="layers-panel" id="layersPanel">
+            <div class="layers-header">
+                <span class="layers-title">图层</span>
+                <button class="layers-close" id="layersClose">×</button>
+            </div>
+            <div class="layers-list" id="layersList">
+                <!-- 图层项将动态生成 -->
+            </div>
+            <div class="layers-actions">
+                <button class="layers-btn" id="layerToggleVisible" title="显示/隐藏">👁</button>
+            </div>
+        </div>
     </div>
 
     <input type="file" id="fileInput" accept="image/*" hidden>