feat(gallery): Ext.Cameras 1.0.3 —— 子插件装完当场生效（免重启）

- 相机宿主实现 ISubPluginHotActivate：全新安装的插件装完立即加载注册，不必重启程序
- 更新已加载的插件仍需重启（net48 程序集不可卸载、dll 被占用），照实提示原因
- 索引按发布仓实际文件重算 size/sha256，避免安装时校验报 大小不匹配

index.json

@@ -1,6 +1,6 @@
 {
     "schemaVersion":  1,
-    "generatedAt":  "2026-09-26T07:33:23Z",
+    "generatedAt":  "2026-09-26T07:58:42Z",
     "packages":  [
                      {
                          "id":  "Plugins.Camera",
@@ -459,12 +459,12 @@
                      {
                          "id":  "Ext.Cameras",
                          "name":  "相机",
-                         "version":  "1.0.2",
+                         "version":  "1.0.3",
                          "publisher":  "TeamAAS",
                          "description":  "相机模块：设备管理、连接/采集、曝光/增益调节与实时预览（内置 USB(UVC) 相机与仿真相机；其他品牌驱动以扩展插件形式接入）。",
-                         "downloadUrl":  "packages/platform/Ext.Cameras/Ext.Cameras-1.0.2.zip",
-                         "sha256":  "6ec0ce96fc6a001c2ca5068f744bb2a2824e7655fac68ccd1030cf45da28df32",
-                         "size":  41056056,
+                         "downloadUrl":  "packages/platform/Ext.Cameras/Ext.Cameras-1.0.3.zip",
+                         "sha256":  "9410fa820e7478a0cf1ee3d8573c36ff2732927e60ed5d4de204f344e15744ae",
+                         "size":  41057138,
                          "notes":  "• 设备管理、连接/采集、曝光增益调节与实时预览\n• 内置 USB(UVC) 相机与仿真相机\n• 其他品牌驱动以插件形式扩展接入",
                          "targetFramework":  "net48",
                          "references":  [
@@ -479,6 +479,15 @@
                                                     "OpenCvSharpExtern.dll"
                                                 ],
                          "versions":  [
+                                          {
+                                              "version":  "1.0.3",
+                                              "downloadUrl":  "packages/platform/Ext.Cameras/Ext.Cameras-1.0.3.zip",
+                                              "sha256":  "9410fa820e7478a0cf1ee3d8573c36ff2732927e60ed5d4de204f344e15744ae",
+                                              "size":  41057138,
+                                              "releasedAt":  "2026-09-26",
+                                              "status":  "stable",
+                                              "notes":  "• 设备管理、连接/采集、曝光增益调节与实时预览\n• 内置 USB(UVC) 相机与仿真相机\n• 其他品牌驱动以插件形式扩展接入"
+                                          },
                                           {
                                               "version":  "1.0.2",
                                               "downloadUrl":  "packages/platform/Ext.Cameras/Ext.Cameras-1.0.2.zip",