fix: improve conversation and report stability

server/im_http_test.go

@@ -2442,6 +2442,46 @@ func TestServeIMMonthlyReportsCreate(t *testing.T) {
 	}
 }
 
+func TestServeIMMonthlyReportsListIncludesPreviews(t *testing.T) {
+	ctrl := gomock.NewController(t)
+	defer ctrl.Finish()
+	expectIMBearer(t, ctrl, "token-1", 7, 42)
+	oldMonthlyReports := store.MonthlyReports
+	now := time.Now().UTC().Round(time.Millisecond)
+	reports := &testMonthlyReportsStore{report: &types.MonthlyReport{
+		ReportID:    "mr_test",
+		AuthorID:    42,
+		Month:       "2026-08",
+		WorkSummary: strings.Repeat("工作", 80),
+		NextPlan:    " 下月计划一 \n 下月计划二 ",
+		Status:      types.DailyReportStatusDraft,
+		ReadState:   "unread",
+		Version:     1,
+		CreatedAt:   now,
+		UpdatedAt:   now,
+	}}
+	store.MonthlyReports = reports
+	defer func() { store.MonthlyReports = oldMonthlyReports }()
+
+	req := httptest.NewRequest(http.MethodGet, "/v1/im/reports/monthly?scope=mine", nil)
+	req.Header.Set("Authorization", "Bearer token-1")
+	rec := httptest.NewRecorder()
+	serveIMMonthlyReports(rec, req)
+
+	if rec.Code != http.StatusOK {
+		t.Fatalf("status: got %d, want %d; body=%s", rec.Code, http.StatusOK, rec.Body.String())
+	}
+	data := decodeIMHTTPResponse(t, rec).Data.(map[string]any)
+	items := data["items"].([]any)
+	item := items[0].(map[string]any)
+	if item["work_summary_short"] != strings.Repeat("工作", 60)+"..." {
+		t.Fatalf("unexpected work summary preview: %#v", item["work_summary_short"])
+	}
+	if item["next_plan_short"] != "下月计划一 下月计划二" {
+		t.Fatalf("unexpected next plan preview: %#v", item["next_plan_short"])
+	}
+}
+
 func TestServeIMMonthlyReportDraftAndSubmit(t *testing.T) {
 	ctrl := gomock.NewController(t)
 	defer ctrl.Finish()