feat(office): mail preview, infinite scroll, pane resize, and scrollbars

Polish the office TUI with proportional pane layout, drag resize, live
filtering, HTML mail preview, paginated mail lists, overflow scrollbars,
flattened navigation, and project save/status fixes; add UpdateProjectStatus.

Co-authored-by: Cursor <cursoragent@cursor.com>

cmd/office/fetch/save.go

@@ -10,29 +10,50 @@ import (
 )
 
 // SaveItem persists editable form fields for supported entity kinds.
-func (l *Loader) SaveItem(ctx context.Context, item model.Item, title, description string) error {
+func (l *Loader) SaveItem(ctx context.Context, item model.Item, fields model.FormFields) error {
 	if l == nil || l.Client == nil {
 		return fmt.Errorf("fetch: client is nil")
 	}
 	switch item.Kind {
 	case model.KindTask:
-		return l.UpdateTask(ctx, item.ID, title, description)
+		return l.UpdateTask(ctx, item.ID, fields.Primary, fields.Secondary)
 	case model.KindProject:
-		id, err := strconv.Atoi(item.ID)
-		if err != nil {
-			return err
-		}
-		_, err = l.Client.UpdateProject(onlyoffice.ProjectUpdateRequest{
-			ID:          id,
-			Title:       title,
-			Description: description,
-		})
-		return err
+		return l.saveProject(ctx, item.ID, fields)
 	default:
 		return fmt.Errorf("save not supported for %s", item.Kind)
 	}
 }
 
+func (l *Loader) saveProject(ctx context.Context, projectID string, fields model.FormFields) error {
+	id, err := strconv.Atoi(projectID)
+	if err != nil {
+		return err
+	}
+	if fields.ResponsibleID == "" {
+		raw, derr := l.Detail(ctx, model.Item{ID: projectID, Kind: model.KindProject})
+		if derr == nil {
+			fields.ResponsibleID = model.ResponsibleIDFromRaw(raw)
+		}
+	}
+	req := onlyoffice.ProjectUpdateRequest{
+		ID:          id,
+		Title:       fields.Primary,
+		Description: fields.Secondary,
+	}
+	if fields.ResponsibleID != "" {
+		req.ResponsibleID = fields.ResponsibleID
+	}
+	if _, err := l.Client.UpdateProject(req); err != nil {
+		return err
+	}
+	if fields.HasStatus {
+		if _, err := l.Client.UpdateProjectStatus(id, string(fields.Status)); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
 // DetailForm loads form field values for the detail pane.
 func (l *Loader) DetailForm(ctx context.Context, item model.Item) (model.FormFields, error) {
 	raw, err := l.Detail(ctx, item)