feat: scan page redesign — fixed 2x zoom, torch, camera flip, tabs, recents, AI number OCR

- Always-on 2x hardware zoom (CSS scale fallback)
- Torch button with toggle + visual feedback
- Camera flip (front/back) with settings persistence
- 3-tab input panel: Barcode / Name / AI
- Recent products chips (last 6 scanned, from localStorage)
- Live barcode code overlay during partial detection
- Confirm overlay (checkmark + name) on successful scan
- AI number OCR (Gemini reads barcode digits from image, shown after 4s)
- Guide corners frame in viewport
- PHP: gemini_number_ocr action + rate-limited
- Translations: new scan.* keys in it/en/de

translations/de.json

@@ -170,10 +170,26 @@
     "qty_trace": "< 1"
   },
   "scan": {
-    "title": "Produkt scannen",
+    "title": "Scannen",
     "mode_shopping": "🛒 Einkaufsmodus",
     "mode_shopping_end": "✅ Einkauf beenden",
+    "spesa_btn": "🛒 Einkauf",
     "zoom": "Zoom",
+    "tab_barcode": "Barcode",
+    "tab_name": "Name",
+    "tab_ai": "KI",
+    "recents_label": "Zuletzt",
+    "torch_hint": "Taschenlampe",
+    "torch_on": "Taschenlampe an",
+    "torch_off": "Taschenlampe aus",
+    "torch_unavailable": "Taschenlampe auf diesem Gerät nicht verfügbar",
+    "flip_hint": "Kamera wechseln",
+    "flip_front": "Frontkamera",
+    "flip_back": "Rückkamera",
+    "num_ocr_btn": "🔢 Zahlen mit KI lesen",
+    "num_ocr_searching": "Suche Barcode mit KI...",
+    "num_ocr_found": "Code gefunden: {code}",
+    "num_ocr_not_found": "Kein Barcode im Bild gefunden",
     "barcode_placeholder": "Barcode eingeben...",
     "quick_name_divider": "oder Name eingeben",
     "quick_name_placeholder": "z.B.: Äpfel, Zucchini, Brot...",