add debug option

frontend/src/pages/SettingsPage.jsx

@@ -388,6 +388,24 @@ const SettingsPage = () => {
                 <span className="form-hint">Désactiver pour debug manuel</span>
               </div>
 
+              <div className="form-group">
+                <label>Mode debug</label>
+                <label className="checkbox-label">
+                  <input
+                    type="checkbox"
+                    checked={backendConfig.scrape?.debug_enabled ?? false}
+                    onChange={(e) =>
+                      setBackendConfig({
+                        ...backendConfig,
+                        scrape: { ...backendConfig.scrape, debug_enabled: e.target.checked },
+                      })
+                    }
+                  />
+                  Sauvegarder screenshots et HTML
+                </label>
+                <span className="form-hint">Génère des artifacts de debug dans backend/app/samples/debug/</span>
+              </div>
+
               <div className="form-group">
                 <label>Timeout (ms)</label>
                 <input