fix: AI visual barcode fallback fires only once per scanner session

If Gemini cannot identify the product visually, mark _aiFallbackExhausted=true
for the current scanner session so the 5s timer never fires again. The scanner
restarts normally (user can keep trying with the barcode reader) and a persistent
status message is shown: 'AI: product not recognized — try scanning the barcode'.
_aiFallbackExhausted resets to false in stopScanner() so the next camera session
starts fresh.

assets/js/app.js

@@ -1944,6 +1944,7 @@ let aiStream = null;
 let _scanZoomLevel = 2; // always 2x
 let _torchActive = false;
 let _aiFallbackTimer = null;
+let _aiFallbackExhausted = false; // true after one failed AI visual attempt — reset when scanner is closed
 
 // Apply fixed 2x zoom (hardware if available, CSS fallback)
 async function _applyFixedZoom() {
@@ -2174,17 +2175,19 @@ async function _tryGeminiVisualBarcode() {
                 showToast(t('error.connection'), 'error');
             }
         } else {
-            scanLog('AI visual: product not identified');
+            scanLog('AI visual: product not identified — exhausted for this session');
+            _aiFallbackExhausted = true;
             showLoading(false);
-            showToast(t('scan.ai_fallback_not_found'), 'warning');
-            _setScanStatus(t('scan.status_ready'), '', '');
-            // Restart scanner so user can try again
+            _setScanStatus(t('scan.ai_fallback_exhausted'), 'retry', '');
+            // Restart the scanner so the user can keep trying with the barcode reader,
+            // but the 5s AI timer will NOT fire again (_aiFallbackExhausted=true).
             setTimeout(() => initScanner(), 300);
         }
     } catch (e) {
         scanLog(`AI visual error: ${e.message}`);
+        _aiFallbackExhausted = true;
         showLoading(false);
-        showToast(t('error.connection'), 'error');
+        _setScanStatus(t('scan.ai_fallback_exhausted'), 'retry', '');
         setTimeout(() => initScanner(), 300);
     } finally {
         _aiBarcodeVisualRunning = false;
@@ -6615,10 +6618,10 @@ async function initScanner() {
         }
 
         // After 5s without a scan, auto-trigger AI visual identification (if enabled)
-        if (_geminiAvailable && getSettings().barcode_ai_fallback) {
+        if (_geminiAvailable && getSettings().barcode_ai_fallback && !_aiFallbackExhausted) {
             clearTimeout(_aiFallbackTimer);
             _aiFallbackTimer = setTimeout(() => {
-                if (scannerStream) { // still scanning — no barcode found yet
+                if (scannerStream && !_aiFallbackExhausted) { // still scanning — no barcode found yet
                     scanLog('5s elapsed without barcode — triggering AI visual fallback');
                     _tryGeminiVisualBarcode();
                 }
@@ -6948,6 +6951,7 @@ function stopScanner() {
     _scanZoomLevel = 2; // always 2x on next start
     _torchActive = false;
     clearTimeout(_aiFallbackTimer); _aiFallbackTimer = null;
+    _aiFallbackExhausted = false; // reset so a new scanner session can try again
     if (scannerStream) {
         scannerStream.getTracks().forEach(t => t.stop());
         scannerStream = null;

translations/de.json

@@ -223,7 +223,8 @@
     "status_parallel": "Kombinierter Scan aktiv...",
     "ai_fallback_searching": "KI identifiziert Produkt...",
     "ai_fallback_found": "Produkt von KI erkannt",
-    "ai_fallback_not_found": "KI: Produkt nicht erkannt"
+    "ai_fallback_not_found": "KI: Produkt nicht erkannt",
+    "ai_fallback_exhausted": "KI: Produkt nicht erkannt — Barcode erneut scannen"
   },
   "action": {
     "title": "Was möchtest du tun?",

translations/en.json

@@ -223,7 +223,8 @@
     "status_parallel": "Using combined scan methods...",
     "ai_fallback_searching": "AI identifying product...",
     "ai_fallback_found": "Product identified by AI",
-    "ai_fallback_not_found": "AI: product not recognized"
+    "ai_fallback_not_found": "AI: product not recognized",
+    "ai_fallback_exhausted": "AI: product not recognized — try scanning the barcode"
   },
   "action": {
     "title": "What do you want to do?",

translations/es.json

@@ -220,7 +220,8 @@
     "status_parallel": "Escaneo combinado activo...",
     "ai_fallback_searching": "Identificación de IA en curso...",
     "ai_fallback_found": "Producto identificado por IA",
-    "ai_fallback_not_found": "IA: producto no reconocido"
+    "ai_fallback_not_found": "IA: producto no reconocido",
+    "ai_fallback_exhausted": "IA: producto no reconocido — prueba a escanear el código"
   },
   "action": {
     "title": "¿Qué quieres hacer?",

translations/fr.json

@@ -220,7 +220,8 @@
     "status_parallel": "Scan combiné actif...",
     "ai_fallback_searching": "Identification IA en cours...",
     "ai_fallback_found": "Produit identifié par l'IA",
-    "ai_fallback_not_found": "IA : produit non reconnu"
+    "ai_fallback_not_found": "IA : produit non reconnu",
+    "ai_fallback_exhausted": "IA : produit non reconnu — réessayez avec le code-barres"
   },
   "action": {
     "title": "Que voulez-vous faire ?",

translations/it.json

@@ -223,7 +223,8 @@
     "status_parallel": "Doppia scansione attiva...",
     "ai_fallback_searching": "Identificazione AI in corso...",
     "ai_fallback_found": "Prodotto identificato dall'AI",
-    "ai_fallback_not_found": "AI: prodotto non riconosciuto"
+    "ai_fallback_not_found": "AI: prodotto non riconosciuto",
+    "ai_fallback_exhausted": "AI: prodotto non riconosciuto — riprova con il barcode"
   },
   "action": {
     "title": "Cosa vuoi fare?",