fix: QShortcut import - move from QtWidgets to QtGui

QShortcut is in PyQt6.QtGui, not PyQt6.QtWidgets.
This fixes the ImportError on Windows.

core/perfect_ux.py

@@ -29,7 +29,7 @@ from PyQt6.QtWidgets import (
     QStackedWidget, QLabel, QPushButton, QFrame,
     QScrollArea, QGridLayout, QSizePolicy, QSpacerItem,
     QGraphicsDropShadowEffect, QProgressBar, QToolTip,
-    QDialog, QLineEdit, QTextEdit, QShortcut
+    QDialog, QLineEdit, QTextEdit
 )
 from PyQt6.QtCore import (
     Qt, QTimer, pyqtSignal, QSize, QPropertyAnimation,
@@ -37,7 +37,7 @@ from PyQt6.QtCore import (
 )
 from PyQt6.QtGui import (
     QColor, QPainter, QLinearGradient, QFont, QIcon,
-    QFontDatabase, QPalette, QCursor, QKeySequence
+    QFontDatabase, QPalette, QCursor, QKeySequence, QShortcut
 )
 
 from core.eu_styles import get_all_colors