claude fix: improve product scraping and debugging features

backend/app/api/routes_scrape.py

@@ -1,12 +1,29 @@
 from __future__ import annotations
 
-from fastapi import APIRouter, BackgroundTasks
+from fastapi import APIRouter, BackgroundTasks, HTTPException
+from pydantic import BaseModel, HttpUrl
 
-from backend.app.scraper.runner import scrape_all, scrape_product
+from backend.app.scraper.runner import scrape_all, scrape_preview, scrape_product
 
 router = APIRouter(prefix="/scrape", tags=["scrape"])
 
 
+class PreviewRequest(BaseModel):
+    url: HttpUrl
+
+
+@router.post("/preview")
+def preview_scrape(payload: PreviewRequest):
+    """
+    Scrape une URL Amazon sans enregistrer en base.
+    Retourne les données pour prévisualisation avant ajout.
+    """
+    result = scrape_preview(str(payload.url))
+    if not result["success"] and result["error"]:
+        raise HTTPException(status_code=422, detail=result["error"])
+    return result
+
+
 @router.post("/product/{product_id}")
 def trigger_single(product_id: int, background_tasks: BackgroundTasks):
     # on délègue le vrai travail à un background task rapide