Keep the project picker reachable while the rail is collapsed

The picker was hidden outright at 54px, on the grounds that a combo box there
could only show a stub of a name. True, but it left the collapsed rail with no
way to change project at all — and the audit page's own inventory of the 11
collapsible controls says the rail's fold "giữ nguyên toàn bộ".

A folder QToolButton stands in for it: same items, and choosing one moves the
combo, so _on_rail_project_pick stays the single code path. Its tooltip carries
the current project name, which the combo could not have shown anyway. It
matches the ＋ button's width and drops its menu arrow — at 42px the arrow
would take a third of the row to say nothing.

check_nav now collapses the rail and requires a reachable picker whose menu
matches the combo item for item, then picks a row and asserts the project
actually changed. Hiding the button fails it.

15/15 checkers pass.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

app.py

@@ -247,10 +247,23 @@ class MainWindow(QMainWindow):
         self.nav_new_chat.setIcon(_icon("plus"))
         self.nav_new_chat.setCursor(Qt.PointingHandCursor)
         self.nav_new_chat.clicked.connect(self._on_rail_new_chat)
+        # At 54px the picker cannot show a name, but dropping it altogether left
+        # the collapsed rail with no way to change project at all. This stands in
+        # for it: same list, same handler, just the folder icon and a tooltip.
+        self.nav_project_btn = QToolButton()
+        self.nav_project_btn.setObjectName("navProjectPickMini")
+        self.nav_project_btn.setIcon(_icon("folder"))
+        self.nav_project_btn.setCursor(Qt.PointingHandCursor)
+        self.nav_project_btn.setPopupMode(QToolButton.InstantPopup)
+        self.nav_project_btn.setSizePolicy(QSizePolicy.Expanding, QSizePolicy.Fixed)
+        self.nav_project_btn.setMenu(QMenu(self.nav_project_btn))
+        self.nav_project_btn.menu().aboutToShow.connect(self._fill_rail_project_menu)
+        self.nav_project_btn.setVisible(False)
         head = QVBoxLayout()
         head.setContentsMargins(6, 0, 6, 6)
         head.setSpacing(6)
         head.addWidget(self.nav_project)
+        head.addWidget(self.nav_project_btn)
         head.addWidget(self.nav_new_chat)
         nvl.addLayout(head)
         self.workspace.project_selected.connect(self._sync_rail_project)
@@ -621,12 +634,28 @@ class MainWindow(QMainWindow):
                 self.nav_project.setCurrentIndex(idx)
             has = bool(choices)
             self.nav_project.setEnabled(has)
+            self.nav_project_btn.setEnabled(has)
+            self.nav_project_btn.setToolTip(
+                self.nav_project.currentText().replace("📁 ", "")
+                if has else tr("app.nav.create_project_first"))
             self.nav_new_chat.setEnabled(has)
             self.nav_new_chat.setToolTip(
                 "" if has else tr("app.nav.create_project_first"))
         finally:
             self._syncing_rail_project = False
 
+    def _fill_rail_project_menu(self) -> None:
+        """Mirror the picker's items. Choosing one moves the picker, which runs
+        _on_rail_project_pick — the collapsed rail adds no second code path."""
+        menu = self.nav_project_btn.menu()
+        menu.clear()
+        for i in range(self.nav_project.count()):
+            act = menu.addAction(self.nav_project.itemText(i))
+            act.setCheckable(True)
+            act.setChecked(i == self.nav_project.currentIndex())
+            act.triggered.connect(
+                lambda _checked=False, row=i: self.nav_project.setCurrentIndex(row))
+
     def _on_rail_project_pick(self, _idx: int) -> None:
         if self._syncing_rail_project:
             return
@@ -701,6 +730,7 @@ class MainWindow(QMainWindow):
         # picker would be a stub of a name, so it steps aside entirely and the
         # button keeps just its ＋ icon.
         self.nav_project.setVisible(not self._nav_collapsed)
+        self.nav_project_btn.setVisible(self._nav_collapsed)
         self._refresh_rail_recents()
         # Collapsed to 54px only the theme toggle still fits; the rest of the
         # account row would be clipped, so it steps aside (Settings, which opens

theme.py

@@ -469,6 +469,16 @@ QComboBox#navProjectPick {
     background: $surface_raised; border: 1px solid $nav_border; color: $text;
     padding: 4px 8px; border-radius: ${radius}px;
 }
+/* Stand-in for the picker while the rail is 54px wide: icon only, no arrow —
+   the arrow would eat a third of the width for no information. */
+QToolButton#navProjectPickMini {
+    background: $surface_raised; border: 1px solid $nav_border; border-radius: ${radius}px;
+    padding: 4px; qproperty-iconSize: 16px 16px;
+}
+QToolButton#navProjectPickMini:hover { background: $nav_hover; }
+QToolButton#navProjectPickMini:disabled { background: transparent; border-color: $border; }
+QToolButton#navProjectPickMini::menu-indicator { image: none; width: 0; }
+
 QPushButton#navSettingsBtn {
     background: transparent; border: none; color: $text_muted;
     padding: 6px 8px 6px 4px; text-align: left; border-radius: ${radius}px;

tools/check_nav.py

@@ -289,6 +289,37 @@ def main() -> int:
     print(f"provider dang chon : {win.provider_combo.currentText()!r}")
     print(f"tai khoan          : {win.account_lbl.text()!r}")
 
+    # Collapsing the rail must not take the project picker away with it: at
+    # 54px the combo cannot show a name, so a folder button stands in for it.
+    if not win._nav_collapsed:
+        win._toggle_nav()
+        app.processEvents()
+    mini = getattr(win, "nav_project_btn", None)
+    if mini is None or mini.isHidden():
+        fails.append("thu gon rail xong khong con cach nao doi project")
+    else:
+        mini.menu().aboutToShow.emit()
+        app.processEvents()
+        menu_items = [a.text() for a in mini.menu().actions()]
+        combo_items = [win.nav_project.itemText(i)
+                       for i in range(win.nav_project.count())]
+        if menu_items != combo_items:
+            fails.append(f"menu project khi thu gon lech voi combo: "
+                         f"{menu_items} vs {combo_items}")
+        elif len(menu_items) > 1:
+            before = win.workspace.selected_project_id()
+            # Any row but the one already selected, or nothing would change.
+            row = (win.nav_project.currentIndex() + 1) % len(menu_items)
+            mini.menu().actions()[row].trigger()
+            app.processEvents()
+            after = win.workspace.selected_project_id()
+            if after == before:
+                fails.append("chon project tu menu thu gon khong doi project")
+            else:
+                print(f"doi project khi thu gon: {before} -> {after}")
+    win._toggle_nav()
+    app.processEvents()
+
     print()
     print(f"tong dong dieu huong: {n_total} + nut Cai dat")
     if fails: