grid: remove unused imports, stop animation before widget deletion

Unused: Path, Post, QPainterPath, QMenu, QApplication.

FlowLayout.clear() now stops any in-flight fade animation before
calling deleteLater() on thumbnails. Without this, a mid-flight
QPropertyAnimation can fire property updates on a widget that's
queued for deletion.

booru_viewer/gui/grid.py

@@ -3,22 +3,17 @@
 from __future__ import annotations
 
 import logging
-from pathlib import Path
 
 log = logging.getLogger("booru")
 
 from PySide6.QtCore import Qt, Signal, QSize, QRect, QRectF, QMimeData, QUrl, QPoint, Property, QPropertyAnimation, QEasingCurve
-from PySide6.QtGui import QPixmap, QPainter, QPainterPath, QColor, QPen, QKeyEvent, QWheelEvent, QDrag, QMouseEvent
+from PySide6.QtGui import QPixmap, QPainter, QColor, QPen, QKeyEvent, QWheelEvent, QDrag, QMouseEvent
 from PySide6.QtWidgets import (
     QWidget,
     QScrollArea,
-    QMenu,
-    QApplication,
     QRubberBand,
 )
 
-from ..core.api.base import Post
-
 THUMB_SIZE = 180
 THUMB_SPACING = 2
 BORDER_WIDTH = 2
@@ -382,6 +377,8 @@ class FlowLayout(QWidget):
 
     def clear(self) -> None:
         for w in self._items:
+            if hasattr(w, '_fade_anim') and w._fade_anim is not None:
+                w._fade_anim.stop()
             w.setParent(None)  # type: ignore
             w.deleteLater()
         self._items.clear()