滚动截图，细节调整

src-tauri/src/constants.rs

@@ -12,6 +12,8 @@ pub mod windows {
     pub const SCREENSHOT_OVERLAY: &str = "screenshot-overlay";
     #[allow(dead_code)]
     pub const SCREENSHOT_PIN: &str = "screenshot-pin";
+    #[allow(dead_code)]
+    pub const SCREENSHOT_SCROLL: &str = "screenshot-scroll";
 }
 
 /// Tauri 事件名（与前端 constants::EVENTS 对应）
@@ -51,6 +53,14 @@ pub mod events {
     // 截图
     pub const SCREENSHOT_SHORTCUT: &str = "screenshot-shortcut";
     pub const SCREENSHOT_PIN_SHORTCUT: &str = "screenshot-pin-shortcut";
+    /// 截图结果导出（含覆盖层/编辑器/滚动截图会话）
+    pub const SCREENSHOT_EXPORTED: &str = "screenshot-exported";
+    /// 滚动截图会话：实时进度 { width, height, auto }
+    pub const SCROLL_PROGRESS: &str = "screenshot-scroll-progress";
+    /// 滚动截图会话：完成并导出（负载与 SCREENSHOT_EXPORTED 相同）
+    pub const SCROLL_COMPLETE: &str = "screenshot-scroll-complete";
+    /// 滚动截图会话：已取消（无负载）
+    pub const SCROLL_CANCELLED: &str = "screenshot-scroll-cancelled";
     // 内核安装进度
     pub const KERNEL_INSTALL_PROGRESS: &str = "kernel-install-progress";
     // 后端自动切换节点完成（前端据以刷新节点列表并提示）