修复 OAuth/SetupToken 转发请求体重排并增加调试开关

backend/internal/service/gateway_debug_env_test.go

@@ -0,0 +1,34 @@
+package service
+
+import "testing"
+
+func TestDebugGatewayBodyLoggingEnabled(t *testing.T) {
+	t.Run("default disabled", func(t *testing.T) {
+		t.Setenv(debugGatewayBodyEnv, "")
+		if debugGatewayBodyLoggingEnabled() {
+			t.Fatalf("expected debug gateway body logging to be disabled by default")
+		}
+	})
+
+	t.Run("enabled with true-like values", func(t *testing.T) {
+		for _, value := range []string{"1", "true", "TRUE", "yes", "on"} {
+			t.Run(value, func(t *testing.T) {
+				t.Setenv(debugGatewayBodyEnv, value)
+				if !debugGatewayBodyLoggingEnabled() {
+					t.Fatalf("expected debug gateway body logging to be enabled for %q", value)
+				}
+			})
+		}
+	})
+
+	t.Run("disabled with other values", func(t *testing.T) {
+		for _, value := range []string{"0", "false", "off", "debug"} {
+			t.Run(value, func(t *testing.T) {
+				t.Setenv(debugGatewayBodyEnv, value)
+				if debugGatewayBodyLoggingEnabled() {
+					t.Fatalf("expected debug gateway body logging to be disabled for %q", value)
+				}
+			})
+		}
+	})
+}