feat(bat): 暴露翻译任务状态控制

Refs #43

internal/backendrpc/client_test.go

@@ -336,6 +336,45 @@ func TestScheduleRunSendsScopeAndMaxRuns(t *testing.T) {
 	}
 }
 
+func TestTranslationTaskUpdateSendsWorkerParams(t *testing.T) {
+	client := newTestClient(t, func(t *testing.T, req testRequest) testResponse {
+		if req.Method != "translation.task.update" {
+			t.Fatalf("method = %s", req.Method)
+		}
+		var params TranslationTaskUpdateParams
+		if err := json.Unmarshal(req.Params, &params); err != nil {
+			t.Fatalf("decode params: %v", err)
+		}
+		if params.TaskID != "textunit/v-current/Scenario" ||
+			params.Status != "failed" ||
+			params.FailureReason != "provider rejected payload" ||
+			params.ProviderRunID != "provider-run-1" {
+			t.Fatalf("params = %#v", params)
+		}
+		return testResponse{
+			Result: testEnvelope{
+				OK:        true,
+				Status:    "ok",
+				RequestID: "req-test-translation-update",
+				Data:      map[string]any{"task_status": "failed"},
+			},
+		}
+	})
+
+	raw, err := client.TranslationTaskUpdate(context.Background(), TranslationTaskUpdateParams{
+		TaskID:        "textunit/v-current/Scenario",
+		Status:        "failed",
+		FailureReason: "provider rejected payload",
+		ProviderRunID: "provider-run-1",
+	})
+	if err != nil {
+		t.Fatalf("TranslationTaskUpdate error: %v", err)
+	}
+	if !json.Valid(raw) {
+		t.Fatalf("invalid raw JSON: %s", string(raw))
+	}
+}
+
 func TestApplicationErrorReturnsAPIError(t *testing.T) {
 	client := newTestClient(t, func(t *testing.T, req testRequest) testResponse {
 		if req.Method != "task.status" {