完善生图5.0的功能

backend/internal/httpapi/jobs.go

@@ -458,10 +458,22 @@ func writeJobError(w http.ResponseWriter, err error, public bool) {
 		message := "生成任务计费失败。"
 		if public {
 			message = "Generation job billing failed."
+		} else if errors.Is(err, billing.ErrInsufficientBalance) {
+			message = "余额不足，请先充值。"
+		} else if errors.Is(err, billing.ErrOrganizationUnavailable) {
+			message = "账号未绑定有效组织，请联系管理员。"
 		}
 		writeJSON(w, billingStatus.Status, map[string]string{"error": message})
 		return
 	}
+	if errors.Is(err, billing.ErrProviderUnavailable) {
+		message := "计费服务暂不可用，请稍后重试。"
+		if public {
+			message = "Generation billing is temporarily unavailable."
+		}
+		writeJSON(w, http.StatusServiceUnavailable, map[string]string{"error": message})
+		return
+	}
 	writeJSON(w, 500, map[string]string{"error": "Internal server error."})
 }
 func randomJobID() string {