fix: hydrate meeting note file uploader

internal/httpapi/payload.go

@@ -335,7 +335,7 @@ func meetingNoteFilePayload(file store.MeetingNoteFile, viewer int64) map[string
 		"preview_mode":     file.PreviewMode,
 		"preview_file_id":  file.PreviewFileID,
 		"uploader_user_id": formatUserID(file.UploaderID),
-		"uploader":         userSummary(file.UploaderID, store.UserSummary{}),
+		"uploader":         userSummary(file.UploaderID, file.Uploader),
 		"version":          file.Version,
 		"permissions": map[string]any{
 			"can_preview":  file.Status == "active",

internal/httpapi/payload_userid_test.go

@@ -115,6 +115,28 @@ func TestMeetingNoteFilePayloadKeepsOriginalNameAndExtension(t *testing.T) {
 	}
 }
 
+func TestMeetingNoteFilePayloadUsesUploaderSummary(t *testing.T) {
+	now := time.Date(2026, 9, 17, 12, 0, 0, 0, time.UTC)
+	payload := meetingNoteFilePayload(store.MeetingNoteFile{
+		NoteFileID: "mnote_1",
+		UploaderID: 1573637795346386944,
+		Uploader: store.UserSummary{
+			UserID:      1573637795346386944,
+			DisplayName: "jcharles3",
+		},
+		Status:    "active",
+		CreatedAt: now,
+		UpdatedAt: now,
+	}, 1573637795346386944)
+	uploader, ok := payload["uploader"].(map[string]any)
+	if !ok {
+		t.Fatalf("uploader=%#v", payload["uploader"])
+	}
+	if uploader["display_name"] != "jcharles3" {
+		t.Fatalf("uploader.display_name=%v, want jcharles3", uploader["display_name"])
+	}
+}
+
 func assertNoNumericUserIDs(t *testing.T, value any) {
 	t.Helper()
 	switch typed := value.(type) {