feat: SessionList.set_mode swaps header for archived view

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/hqt/tui/widgets/session_list.py

@@ -72,6 +72,11 @@ class SessionList(Widget, can_focus=False):
         yield Label("Sessions", id="session-header")
         yield VimListView(id="session-list")
 
+    def set_mode(self, archived: bool) -> None:
+        """Swap the column header to reflect whether archived sessions are shown."""
+        header = self.query_one("#session-header", Label)
+        header.update("Sessions (archived)" if archived else "Sessions")
+
     async def refresh_sessions(
         self, session_infos: list, select_session_id=_UNSET
     ) -> None:

tests/test_tui.py

@@ -2015,3 +2015,23 @@ async def test_h_focuses_projects_l_focuses_sessions(tmp_path):
         await pilot.press("h")
         await pilot.pause()
         assert app.focused is app.query_one("#project-list")
+
+
+@pytest.mark.asyncio
+async def test_session_list_header_reflects_archived_mode():
+    app = HqtApp()
+    async with app.run_test(size=(120, 40)) as pilot:
+        from hqt.tui.widgets.session_list import SessionList
+        from textual.widgets import Label
+
+        sl = app.query_one(SessionList)
+        header = sl.query_one("#session-header", Label)
+        assert str(header.render()) == "Sessions"
+
+        sl.set_mode(archived=True)
+        await pilot.pause()
+        assert "archived" in str(header.render()).lower()
+
+        sl.set_mode(archived=False)
+        await pilot.pause()
+        assert str(header.render()) == "Sessions"