Delta team/fix comment ui v2 (#11)

## Summary

What changed and why?

## Change Type

- [ ] Cowork feature
- [ ] Bug fix
- [ ] Core AI contribution
- [ ] Test / hardening
- [ ] Performance
- [ ] Documentation

## Related Work

Cowork Task:

Core Repo: http://34.143.229.138/gitea-admin/fsg-ai-core-assets

Core AI Issue:

Core Task:

Related PR:

## Scope

What is intentionally included?

What is intentionally NOT included?

## Validation

- [ ] Unit tests
- [ ] Integration tests
- [ ] Manual verification
- [ ] Regression check

Commands / evidence:

## Security Impact

Permission / credential / network / customer data impact:

## Compatibility

- [ ] No breaking change
- [ ] Breaking change documented

## Reviewer Notes

Anything Cowork reviewers should pay attention to.

Reviewed-on: #11
Co-authored-by: Duy Le Huu <duylh19@fpt.com>

presentation/shell/nav_rail.py

@@ -197,9 +197,9 @@ class NavRailMixin:
     def _nav_rows(self):
         """(tree, page, sub, label, icon, enabled) for every row, rail order.
 
-        Workspace contributes all five of its sub-views — including the two the
-        project gate currently disables — so the rail never changes shape while
-        the user is looking at it.
+        Workspace contributes all five of its sub-views; ``_rebuild_nav`` bỏ
+        những hàng mà cổng project đang đóng (Cowork, GraphRAG) thay vì hiện
+        chúng ở dạng mờ.
         """
         rows = [(self.nav, self._ROW_WORKSPACE, sub, label, ic, on)
                 for label, sub, ic, on in self.workspace.nav_entries()]
@@ -238,15 +238,13 @@ class NavRailMixin:
                 tree.clear()
                 tree.blockSignals(blocked)
             for tree, page, sub, label, icon_name, enabled in spec:
+                if not enabled:
+                    # Cổng project đóng → bỏ hẳn hàng, không hiện dạng mờ nữa.
+                    continue
                 it = QTreeWidgetItem([""] if self._nav_collapsed else [label])
                 it.setIcon(0, _icon(icon_name))
                 it.setData(0, Qt.UserRole, {"page": page, "sub": sub})
-                if not enabled:
-                    # Same gate as before, shown instead of hidden: the row stays
-                    # in place, greyed, and says why it cannot be opened.
-                    it.setDisabled(True)
-                    it.setToolTip(0, tr("app.nav.needs_project"))
-                elif self._nav_collapsed:
+                if self._nav_collapsed:
                     it.setToolTip(0, label)
                 blocked = tree.blockSignals(True)
                 tree.addTopLevelItem(it)

presentation/shell/rail_project.py

@@ -42,6 +42,12 @@ class RailProjectMixin:
                 # No project yet: say so, and say what to do about it, instead of
                 # leaving an empty box and a button that silently does nothing.
                 self.nav_project.addItem(tr("app.nav.no_project"), "")
+            elif not current:
+                # Có project nhưng CHƯA chọn cái nào (mở app lên, hoặc vừa xoá
+                # project đang mở). Không có mục này thì combo rơi về mục 0 và
+                # chỉ bừa vào project đầu danh sách, trong khi cổng
+                # Cowork/GraphRAG vẫn đóng — hai chỗ nói hai đằng.
+                self.nav_project.insertItem(0, tr("app.nav.pick_project"), "")
             idx = self.nav_project.findData(current)
             if idx >= 0:
                 self.nav_project.setCurrentIndex(idx)