V2.5.0 — Theme gris moderne + fix recadrage

- Theme gris clair moderne avec accents cyan (#00b4d8)
  - Fond #e8e8e8, menus #f2f2f2, boutons blancs, hover cyan
  - Viewer fond gris, vignettes fond blanc
  - Splash screen en theme clair
  - Scrollbars, menus, dialogues tous en gris/cyan
- Fix recadrage : dialogue garde une reference (plus de garbage collection)
- Popup recadrage compact (360px fixe) et non-modal
- A propos adapte au theme clair

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

app/splash.py

@@ -13,7 +13,7 @@ class SplashScreen(QWidget):
         self.setWindowFlags(Qt.WindowType.FramelessWindowHint | Qt.WindowType.WindowStaysOnTopHint)
         self.setAttribute(Qt.WidgetAttribute.WA_TranslucentBackground, False)
         self.setFixedSize(500, 400)
-        self.setStyleSheet("background-color: #0f172a;")
+        self.setStyleSheet("background-color: #f5f5f5; border: 1px solid #d0d0d0;")
 
         layout = QVBoxLayout(self)
         layout.setContentsMargins(40, 30, 40, 30)
@@ -36,14 +36,14 @@ class SplashScreen(QWidget):
         title = QLabel("COPYDEV IMPOSING TOOL")
         title.setAlignment(Qt.AlignmentFlag.AlignCenter)
         title.setFont(QFont("Segoe UI", 18, QFont.Weight.Bold))
-        title.setStyleSheet("color: white;")
+        title.setStyleSheet("color: #2d2d2d;")
         layout.addWidget(title)
 
         # Sous-titre
         subtitle = QLabel("Outil professionnel d'imposition PDF")
         subtitle.setAlignment(Qt.AlignmentFlag.AlignCenter)
         subtitle.setFont(QFont("Segoe UI", 11))
-        subtitle.setStyleSheet("color: #94a3b8;")
+        subtitle.setStyleSheet("color: #666;")
         layout.addWidget(subtitle)
 
         layout.addSpacing(20)
@@ -52,7 +52,7 @@ class SplashScreen(QWidget):
         self._status = QLabel("Demarrage...")
         self._status.setAlignment(Qt.AlignmentFlag.AlignCenter)
         self._status.setFont(QFont("Segoe UI", 9))
-        self._status.setStyleSheet("color: #64748b;")
+        self._status.setStyleSheet("color: #888;")
         layout.addWidget(self._status)
 
         layout.addStretch()
@@ -64,14 +64,14 @@ class SplashScreen(QWidget):
         )
         contact.setAlignment(Qt.AlignmentFlag.AlignCenter)
         contact.setFont(QFont("Segoe UI", 8))
-        contact.setStyleSheet("color: #475569;")
+        contact.setStyleSheet("color: #999;")
         layout.addWidget(contact)
 
         # Copyright
         copy_label = QLabel("2026 CopyDev - Tous droits reserves")
         copy_label.setAlignment(Qt.AlignmentFlag.AlignCenter)
         copy_label.setFont(QFont("Segoe UI", 7))
-        copy_label.setStyleSheet("color: #334155;")
+        copy_label.setStyleSheet("color: #bbb;")
         layout.addWidget(copy_label)
 
         # Centrer sur l'ecran