Merge upstream/main: v0.1.85-v0.1.86 updates

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

backend/internal/repository/github_release_service.go

@@ -18,14 +18,21 @@ type githubReleaseClient struct {
 	downloadHTTPClient *http.Client
 }
 
+type githubReleaseClientError struct {
+	err error
+}
+
 // NewGitHubReleaseClient 创建 GitHub Release 客户端
 // proxyURL 为空时直连 GitHub，支持 http/https/socks5/socks5h 协议
-func NewGitHubReleaseClient(proxyURL string) service.GitHubReleaseClient {
+func NewGitHubReleaseClient(proxyURL string, allowDirectOnProxyError bool) service.GitHubReleaseClient {
 	sharedClient, err := httpclient.GetClient(httpclient.Options{
 		Timeout:  30 * time.Second,
 		ProxyURL: proxyURL,
 	})
 	if err != nil {
+		if proxyURL != "" && !allowDirectOnProxyError {
+			return &githubReleaseClientError{err: fmt.Errorf("proxy client init failed and direct fallback is disabled; set security.proxy_fallback.allow_direct_on_error=true to allow fallback: %w", err)}
+		}
 		sharedClient = &http.Client{Timeout: 30 * time.Second}
 	}
 
@@ -35,6 +42,9 @@ func NewGitHubReleaseClient(proxyURL string) service.GitHubReleaseClient {
 		ProxyURL: proxyURL,
 	})
 	if err != nil {
+		if proxyURL != "" && !allowDirectOnProxyError {
+			return &githubReleaseClientError{err: fmt.Errorf("proxy client init failed and direct fallback is disabled; set security.proxy_fallback.allow_direct_on_error=true to allow fallback: %w", err)}
+		}
 		downloadClient = &http.Client{Timeout: 10 * time.Minute}
 	}
 
@@ -44,6 +54,18 @@ func NewGitHubReleaseClient(proxyURL string) service.GitHubReleaseClient {
 	}
 }
 
+func (c *githubReleaseClientError) FetchLatestRelease(ctx context.Context, repo string) (*service.GitHubRelease, error) {
+	return nil, c.err
+}
+
+func (c *githubReleaseClientError) DownloadFile(ctx context.Context, url, dest string, maxSize int64) error {
+	return c.err
+}
+
+func (c *githubReleaseClientError) FetchChecksumFile(ctx context.Context, url string) ([]byte, error) {
+	return nil, c.err
+}
+
 func (c *githubReleaseClient) FetchLatestRelease(ctx context.Context, repo string) (*service.GitHubRelease, error) {
 	url := fmt.Sprintf("https://api.github.com/repos/%s/releases/latest", repo)