Photo strips, photo d'identité, NFC tap-to-upload

- Photo strips : 2 templates (3 ou 4 photos), toujours 2 strips côte à côte sur un 10x15
- Photo d'identité : écran dédié, cadrage 35x45mm guidé (ovale + ligne yeux), planche 8 photos sur 10x15
- NFC : service nfcpy optionnel, écrit URL upload sur tag NDEF, configurable dans admin
- Config : option NFC on/off ajoutée
- Matériel cible : mini-PC (plus RPi), imprimante DNP DS-RX1HS

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

src/ui/main_window.py

@@ -6,6 +6,7 @@ from ui.screens.home_screen import HomeScreen
 from ui.screens.import_screen import ImportScreen
 from ui.screens.editor_screen import EditorScreen
 from ui.screens.print_screen import PrintScreen
+from ui.screens.id_photo_screen import IdPhotoScreen
 
 
 class MainWindow(QMainWindow):
@@ -22,11 +23,13 @@ class MainWindow(QMainWindow):
         self.import_screen = ImportScreen(self)
         self.editor_screen = EditorScreen(self)
         self.print_screen = PrintScreen(self)
+        self.id_photo_screen = IdPhotoScreen(self)
 
         self.stack.addWidget(self.home_screen)      # 0
         self.stack.addWidget(self.import_screen)     # 1
         self.stack.addWidget(self.editor_screen)     # 2
         self.stack.addWidget(self.print_screen)      # 3
+        self.stack.addWidget(self.id_photo_screen)   # 4
 
         self.show_home()
 
@@ -45,3 +48,8 @@ class MainWindow(QMainWindow):
         if image_path:
             self.print_screen.set_image(image_path)
         self.stack.setCurrentIndex(3)
+
+    def show_id_photo(self, image_path=None):
+        if image_path:
+            self.id_photo_screen.load_image(image_path)
+        self.stack.setCurrentIndex(4)