style: clear the basedpyright gate for the new-code lines

Narrow QApplication.instance() before use, wrap the theme QSettings
read in str(), hand QPropertyAnimation a real QByteArray, and declare
the lazily-set watch-mode attributes on the class.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/aare/gui/main_window.py

@@ -15,7 +15,17 @@ from aarecommon.models.models import (
     SessionsStateEnum,
     TokenData,
 )
-from PySide6.QtCore import QEvent, QObject, QPropertyAnimation, QSettings, Qt, QTimer, Signal, Slot
+from PySide6.QtCore import (
+    QByteArray,
+    QEvent,
+    QObject,
+    QPropertyAnimation,
+    QSettings,
+    Qt,
+    QTimer,
+    Signal,
+    Slot,
+)
 from PySide6.QtGui import (
     QAction,
     QActionGroup,
@@ -149,6 +159,8 @@ class MainWindow(QMainWindow):
     # declared for the basedpyright gate.
     _session_operations_enabled: bool | None = None
     _default_dock_split_done: bool = False
+    _pre_watch_dock_state: QByteArray | None = None
+    _pre_watch_visibility: list[tuple[QWidget, bool]] | None = None
 
     def __init__(
         self,
@@ -218,7 +230,9 @@ class MainWindow(QMainWindow):
 
         # App-level, not window-level: dialogs and pop-outs get it too.
         self._clickable_cursor_filter = ClickableCursorFilter(self)
-        QApplication.instance().installEventFilter(self._clickable_cursor_filter)
+        app = QApplication.instance()
+        assert app is not None
+        app.installEventFilter(self._clickable_cursor_filter)
 
         # Wheel safety: sliders/spin boxes/combos only react to the wheel
         # while the right mouse button is held; a bare wheel just scrolls
@@ -1737,6 +1751,7 @@ class MainWindow(QMainWindow):
         # Native primitives QSS can't recolor (spin/combo arrow glyphs) draw
         # from the app palette — flip its text roles with the theme.
         app = QApplication.instance()
+        assert isinstance(app, QApplication)  # palette() lives on QApplication
         if not hasattr(self, "_default_palette"):
             self._default_palette = app.palette()
         if self._theme_mode == THEME_PORTRAIT:
@@ -1763,7 +1778,7 @@ class MainWindow(QMainWindow):
         overlay.show()
         effect = QGraphicsOpacityEffect(overlay)
         overlay.setGraphicsEffect(effect)
-        fade = QPropertyAnimation(effect, b"opacity", overlay)
+        fade = QPropertyAnimation(effect, QByteArray(b"opacity"), overlay)
         fade.setDuration(THEME_FADE_MS)
         fade.setStartValue(1.0)
         fade.setEndValue(0.0)
@@ -1772,7 +1787,8 @@ class MainWindow(QMainWindow):
 
     def _restore_theme_settings(self) -> None:
         settings = QSettings("PSI", "AareGUI")
-        self._theme_mode = settings.value("appearance/theme", THEME_ORIGINAL, type=str)
+        # str() wrap: settings.value is typed object even with type=str.
+        self._theme_mode = str(settings.value("appearance/theme", THEME_ORIGINAL, type=str))
 
     def _save_theme_settings(self) -> None:
         settings = QSettings("PSI", "AareGUI")
@@ -2439,7 +2455,7 @@ class MainWindow(QMainWindow):
             *self.findChildren(PopoutWindow),
         ]
         if owned:
-            for widget, was_visible in getattr(self, "_pre_watch_visibility", []):
+            for widget, was_visible in self._pre_watch_visibility or []:
                 widget.setVisible(was_visible)
             # Docks restore via restoreState, not per-dock setVisible: a dock
             # TABBED BEHIND another is isHidden() at snapshot time, so a
@@ -2447,7 +2463,7 @@ class MainWindow(QMainWindow):
             # (the vanished Sample List). restoreState also brings back
             # tab order, the active tab and dock sizes. Needs objectNames
             # on every dock.
-            state = getattr(self, "_pre_watch_dock_state", None)
+            state = self._pre_watch_dock_state
             if state is not None:
                 self.restoreState(state)
         else: