Phase 4.F：微信截图分享 type=2 / 远端图分享 type=其它

按 msext gameController.m:637-678 字面行为，WechatShare 按 content.type
分发：
- type=1 → shareLink（已有）
- type=2 → captureScreenshot → JPEG 0.6 + thumb 0.4x → shareImage
- type=其它 → downloadRemote(URL) → JPEG 0.9 + thumb 0.4x → shareImage

新增：
- ImageProvider.scaledThumb(_:scale:)：等价 msext FuncPublic
  imageByScalingAndCroppingForSize 0.4x 缩放；微信 SDK setThumbImage:
  内部再压到 32KB
- WeChatManager.ShareImage 结构 + shareImage(_:scene:) 异步包装
  （WXImageObject + WXMediaMessage.setThumbImage，FIFO 串行复用 sharePending）

契约：与 type=1 一致，调成功 → sharesuccess 反向 callback（success/cancelled
都发）；errCode=-2 → cancelled；其它 errCode → failed。

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

ylgamehall/Source/SDK/WeChat/WeChatManager.swift

@@ -69,6 +69,19 @@ public final class WeChatManager: NSObject {
         }
     }
 
+    /// 图片分享载荷（type=2 截图 / type=3 远端图）。
+    /// imageData 是大图原始字节（JPEG 等），thumb 是缩略图源 — SDK
+    /// `setThumbImage:` 内部把 thumb 压到 32KB。
+    public struct ShareImage {
+        public let imageData: Data
+        public let thumb:     UIImage
+
+        public init(imageData: Data, thumb: UIImage) {
+            self.imageData = imageData
+            self.thumb = thumb
+        }
+    }
+
     /// 链接分享（FIFO 串行）。微信回包不携带配对 ID，连续调时按入队顺序消费。
     public func shareLink(_ link: ShareLink, scene: ShareScene) async throws {
         #if canImport(WechatOpenSDK)
@@ -97,6 +110,35 @@ public final class WeChatManager: NSObject {
         #endif
     }
 
+    /// 图片分享（FIFO 串行，复用 sharePending）。msext gameController.m:637-678
+    /// type=2 截图 / type=其它 远端图 共用同一条 WXImageObject + setThumbImage 路径。
+    public func shareImage(_ img: ShareImage, scene: ShareScene) async throws {
+        #if canImport(WechatOpenSDK)
+        try await withCheckedThrowingContinuation { (cont: CheckedContinuation<Void, Error>) in
+            sharePending.append(cont)
+
+            let media = WXImageObject()
+            media.imageData = img.imageData
+
+            let message = WXMediaMessage()
+            // 图片分享不需要 title / description（msext 字面：传 nil；这里传空串等价）
+            message.mediaObject = media
+            message.setThumbImage(img.thumb)
+
+            let req = SendMessageToWXReq()
+            req.bText = false
+            req.message = message
+            switch scene {
+            case .session:  req.scene = Int32(WXSceneSession.rawValue)
+            case .timeline: req.scene = Int32(WXSceneTimeline.rawValue)
+            }
+            WXApi.send(req)
+        }
+        #else
+        throw WeChatError.sdkNotLinked
+        #endif
+    }
+
     // MARK: - Internal: resolve callbacks
 
     fileprivate func resolveAuth(state: String, code: String?, errCode: Int) {

ylgamehall/Source/Share/ImageProvider.swift

@@ -39,6 +39,22 @@ public enum ImageProvider {
         }
     }
 
+    /// 等比缩放图片用作微信分享的缩略图源。默认 0.4x 与 msext
+    /// `imageByScalingAndCroppingForSize:CGSizeMake(w*0.4, h*0.4)` 等价
+    /// （gameController.m:656 / 677 字面常量）。微信 SDK `setThumbImage:`
+    /// 内部会再压缩至 32KB，外层只需把图像尺寸压低，避免传 4K 截图过 SDK 时
+    /// 内部 JPEG 编码出超大缩略图。
+    public static func scaledThumb(_ image: UIImage, scale: CGFloat = 0.4) -> UIImage {
+        let target = CGSize(
+            width:  max(1, image.size.width  * scale),
+            height: max(1, image.size.height * scale)
+        )
+        let renderer = UIGraphicsImageRenderer(size: target)
+        return renderer.image { _ in
+            image.draw(in: CGRect(origin: .zero, size: target))
+        }
+    }
+
     /// 下载远端 URL → UIImage。仅简单 URLSession 同步路径，无重试 / 缓存。
     public static func downloadRemote(_ urlString: String) async throws -> UIImage {
         guard let url = URL(string: urlString) else {

ylgamehall/Source/Share/WechatShare.swift

@@ -9,6 +9,7 @@
 //
 
 import Foundation
+import UIKit
 
 #if canImport(WechatOpenSDK)
 import WechatOpenSDK
@@ -37,18 +38,44 @@ public final class WechatShare: SharePlatform {
             return .notInstalled(platform: name)
         }
         let wxScene: WeChatManager.ShareScene = (scene == .timeline) ? .timeline : .session
-        // 当前仅链接分享（type == "1"）走真实 SDK；截图 / 远端图分享待 Phase 4.F 接入
-        // WXImageObject + WXMediaMessage.thumbData
         do {
+            switch content.type {
+            case "1":
+                // 链接分享（msext gameController.m:613-635）
                 try await WeChatManager.shared.shareLink(
                     .init(
                         url: content.webpageUrl,
                         title: content.title,
                         desc: content.desc,
-                    thumbnailURL: nil   // type=2/3 缩略图待 Phase 4.F
+                        thumbnailURL: nil
                     ),
                     scene: wxScene
                 )
+            case "2":
+                // 截图分享（msext gameController.m:637-658）
+                let shot = try ImageProvider.captureScreenshot()
+                guard let imageData = shot.jpegData(compressionQuality: 0.6) else {
+                    return .failed(reason: "screenshot JPEG encode failed")
+                }
+                let thumb = ImageProvider.scaledThumb(shot)
+                try await WeChatManager.shared.shareImage(
+                    .init(imageData: imageData, thumb: thumb),
+                    scene: wxScene
+                )
+            default:
+                // 远端图分享（msext gameController.m:659-680：type 是其它值就当 URL 远端图）
+                let remote = try await ImageProvider.downloadRemote(content.webpageUrl)
+                // msext 直接用原始 data 作为大图；这里 UIImage 已是 decode 后的，
+                // 用 jpegData 重新编码维持等价（避免持有未压缩的原始字节膨胀）。
+                guard let imageData = remote.jpegData(compressionQuality: 0.9) else {
+                    return .failed(reason: "remote image JPEG encode failed")
+                }
+                let thumb = ImageProvider.scaledThumb(remote)
+                try await WeChatManager.shared.shareImage(
+                    .init(imageData: imageData, thumb: thumb),
+                    scene: wxScene
+                )
+            }
             return .success
         } catch let WeChatError.shareFailed(errCode) {
             if errCode == -2 { return .cancelled }