feat(Photos): 添加图片拖拽功能以改善用户体验

为Photos组件添加了鼠标拖拽功能，用户可以通过拖拽来移动放大后的图片。同时，引入了偏移量变量和鼠标事件处理函数，确保拖拽行为平滑且响应迅速。

lib/layer-vue.es.js

@@ -696,18 +696,47 @@ var _sfc_main$2 = defineComponent(_objectSpread$3(_objectSpread$3({}, __default_
       return res;
     });
     var scale = ref(1);
+    var offsetX = ref(0);
+    var offsetY = ref(0);
+    var isDragging = ref(false);
+    var startX = ref(0);
+    var startY = ref(0);
+    var initialOffsetX = ref(0);
+    var initialOffsetY = ref(0);
     var handleWheel = function handleWheel2(event) {
       var delta = event.deltaY > 0 ? -0.1 : 0.1;
       var newScale = scale.value + delta;
       scale.value = Math.min(Math.max(newScale, 0.5), 3);
     };
+    var handleMouseDown = function handleMouseDown2(event) {
+      isDragging.value = true;
+      startX.value = event.clientX;
+      startY.value = event.clientY;
+      initialOffsetX.value = offsetX.value;
+      initialOffsetY.value = offsetY.value;
+    };
+    var handleMouseMove = function handleMouseMove2(event) {
+      if (isDragging.value) {
+        var deltaX = event.clientX - startX.value;
+        var deltaY = event.clientY - startY.value;
+        offsetX.value = initialOffsetX.value + deltaX;
+        offsetY.value = initialOffsetY.value + deltaY;
+      }
+    };
+    var handleMouseUp = function handleMouseUp2() {
+      isDragging.value = false;
+    };
     return function(_ctx, _cache) {
       return openBlock(), createElementBlock("div", {
         class: "layui-layer-phimg",
         onWheel: withModifiers(handleWheel, ["prevent"]),
         style: normalizeStyle({
-          transform: "scale(".concat(scale.value, ")")
-        })
+          transform: "scale(".concat(scale.value, ") translate(").concat(offsetX.value, "px, ").concat(offsetY.value, "px)")
+        }),
+        onMousedown: handleMouseDown,
+        onMousemove: handleMouseMove,
+        onMouseup: handleMouseUp,
+        onMouseleave: handleMouseUp
       }, [createElementVNode("img", {
         src: __props.imgList[index2.value].src
       }, null, 8, _hoisted_2$2), __props.imgList.length > 0 ? (openBlock(), createElementBlock("div", _hoisted_3$2, [__props.imgList.length > 1 ? (openBlock(), createElementBlock("span", _hoisted_4$1, [createElementVNode("a", {