feat: localise scan screen (12 languages)

Replace all hardcoded Russian strings in ScanScreen and _LoadingDialog
with AppLocalizations keys; add addFromReceiptOrPhoto, chooseMethod,
photoReceipt, photoReceiptSubtitle, photoProducts, photoProductsSubtitle,
recognizing keys to all 12 ARB files and regenerate AppLocalizations.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

client/lib/l10n/app_localizations_hi.dart

@@ -287,4 +287,22 @@ class AppLocalizationsHi extends AppLocalizations {
 
   @override
   String get navRecipes => 'रेसिपी';
+
+  @override
+  String get addFromReceiptOrPhoto => 'रसीद या फ़ोटो से जोड़ें';
+
+  @override
+  String get chooseMethod => 'तरीका चुनें';
+
+  @override
+  String get photoReceipt => 'रसीद की फ़ोटो';
+
+  @override
+  String get photoReceiptSubtitle => 'रसीद से सभी उत्पाद पहचानें';
+
+  @override
+  String get photoProducts => 'उत्पादों की फ़ोटो';
+
+  @override
+  String get photoProductsSubtitle => 'फ्रिज, टेबल, शेल्फ — 3 फ़ोटो तक';
 }