fix: check-update无版本号时download_url优先指向全量包

backend/internal/router/app/info.go

@@ -95,14 +95,20 @@ func handleAppCheckUpdate(c *gin.Context) {
 		return v
 	}
 
-	// 如果没有传入版本号，直接返回最新版本
+	// 如果没有传入版本号，直接返回最新版本（安装器模式，优先全量包）
 	if clientVersion == "" {
 		latestVersion := &allVersions[0]
 
-		// 确定下载地址：优先使用自定义地址
-		downloadURL := latestVersion.FilePath
-		downloadSize := latestVersion.FileSize
-		downloadHash := latestVersion.FileHash
+		// 确定下载地址：无版本号时 download_url 优先指向全量包
+		downloadURL := latestVersion.FullPackagePath
+		downloadSize := latestVersion.FullPackageSize
+		downloadHash := latestVersion.FullPackageHash
+		if downloadURL == "" {
+			// 没有全量包，使用文件路径
+			downloadURL = latestVersion.FilePath
+			downloadSize = latestVersion.FileSize
+			downloadHash = latestVersion.FileHash
+		}
 		if latestVersion.CustomDownloadURL != "" {
 			downloadURL = latestVersion.CustomDownloadURL
 		}
@@ -121,7 +127,14 @@ func handleAppCheckUpdate(c *gin.Context) {
 			"changelog":       latestVersion.Changelog,
 		}
 
-		// 如果有完整包，添加完整包信息
+		// 同时返回补丁包信息（如果有），供客户端增量更新使用
+		if latestVersion.FilePath != "" && latestVersion.FilePath != downloadURL {
+			result["patch_url"] = latestVersion.FilePath
+			result["patch_size"] = latestVersion.FileSize
+			result["patch_hash"] = latestVersion.FileHash
+		}
+
+		// 如果有完整包，也单独返回完整包信息
 		if latestVersion.FullPackagePath != "" {
 			result["full_package_url"] = latestVersion.FullPackagePath
 			result["full_package_size"] = latestVersion.FullPackageSize