fix(browser-fetch): allow baidu source fallback

server/internal/tenant/app/knowledge_url_parser.go

@@ -98,7 +98,7 @@ func (s *KnowledgeService) parseWebsiteKnowledge(ctx context.Context, rawURL str
 				zap.Error(fallbackErr),
 			)
 		}
-		return nil, classifySourceFetchError(rawURL, err)
+		return nil, classifySourceFetchError(rawURL, fmt.Errorf("%w; browser fetch fallback failed: %v", err, fallbackErr))
 	}
 
 	text := normalizeKnowledgeText(item.Content)

server/internal/tenant/app/knowledge_url_parser_test.go

@@ -0,0 +1,39 @@
+package app
+
+import (
+	"fmt"
+	"net/http"
+	"strings"
+	"testing"
+)
+
+func TestBrowserFetchDomainAllowedMatchesSubdomain(t *testing.T) {
+	t.Parallel()
+
+	if !browserFetchDomainAllowed("https://mbd.baidu.com/bh/m/detail/ar_10234112381636647949", []string{"baidu.com"}) {
+		t.Fatalf("expected baidu.com to allow mbd.baidu.com")
+	}
+	if browserFetchDomainAllowed("https://notbaidu.com/article", []string{"baidu.com"}) {
+		t.Fatalf("expected baidu.com not to allow notbaidu.com")
+	}
+}
+
+func TestClassifiedSourceFetchErrorIncludesBrowserFallbackFailure(t *testing.T) {
+	t.Parallel()
+
+	err := classifySourceFetchError("https://mbd.baidu.com/article", fmt.Errorf(
+		"webpage parser failed: status=%d body=invalid link; browser fetch fallback failed: domain is not allowed",
+		http.StatusInternalServerError,
+	))
+
+	message := err.Error()
+	for _, expected := range []string{
+		"source website fetch restricted status=500",
+		"webpage parser failed",
+		"browser fetch fallback failed: domain is not allowed",
+	} {
+		if !strings.Contains(message, expected) {
+			t.Fatalf("classified error = %q, want %q", message, expected)
+		}
+	}
+}