Strip pellicule horizontal 4 photos + impression 2 bandes 10x15 paysage

- Strip: 4 photos cote a cote style pellicule avec perforations
- Impression: 2 bandes identiques sur 10x15 paysage
- Apercu: montre une seule bande, imprime les 2
- Multi-shot: defaut 4 photos au lieu de 3

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

backend/main.py

@@ -16,7 +16,7 @@ from backend.config import (
 from backend.camera import camera
 from backend.gallery import lister_photos, compter_photos, supprimer_photo, vider_galerie
 from backend.effects import appliquer_filtre, appliquer_overlay, chroma_key, lister_overlays, lister_fonds, FILTRES
-from backend.collage import creer_strip, creer_collage
+from backend.collage import creer_strip, creer_collage, creer_impression_strip
 from backend.destinations import distribuer_photo, detecter_usb, compteur_restant, reset_compteur
 from backend.printer import lister_imprimantes, imprimer
 from backend.mailer import envoyer_photo
@@ -192,8 +192,15 @@ async def api_strip(donnees: dict):
     for c in chemins:
         if not c.exists():
             return JSONResponse({"erreur": f"Photo introuvable : {c.name}"}, status_code=404)
-    chemin = creer_strip(chemins)
-    return {"nom": chemin.name, "chemin": f"/data/exports/{chemin.name}"}
+    chemin_strip = creer_strip(chemins)
+    # Creer aussi la page d'impression (2 bandes sur 10x15 paysage)
+    chemin_print = creer_impression_strip(chemin_strip)
+    return {
+        "nom": chemin_strip.name,
+        "chemin": f"/data/exports/{chemin_strip.name}",
+        "impression": chemin_print.name,
+        "chemin_impression": f"/data/exports/{chemin_print.name}",
+    }
 
 
 @app.post("/api/collage")