feat: dish recognition UX, background mode, and backend bug fixes

Flutter client:
- Progress dialog: redesigned with pulsing animated icon, info hint about
  background mode, full-width Minimize button; dismiss signal via ValueNotifier
  so the dialog always closes regardless of widget lifecycle
- Background recognition: when user taps Minimize, wasMinimizedByUser flag is
  set; on completion a snackbar is shown instead of opening DishResultSheet
  directly; snackbar action opens the sheet on demand
- Fix dialog spinning forever: finally block guarantees dismissSignal=true on
  all exit paths including early returns from context.mounted checks
- Fix DishResultSheet not appearing: add ValueKey to _DailyMealsSection and
  meal card Padding so Flutter reuses elements when _TodayJobsWidget is
  inserted/removed from the SliverChildListDelegate list
- todayJobsProvider refresh: added refresh() method; called after job submit
  and on DishJobDone; all ref.read() calls guarded with context.mounted checks
- food_search_sheet: scan buttons replaced with full-width stacked OutlinedButtons
- app.dart: WidgetsBindingObserver refreshes scan providers on app resume
- L10n: added dishRecognitionHint and minimize keys to all 12 locales

Backend:
- migrations/003: ALTER TYPE recipe_source ADD VALUE 'recommendation' to fix
  22P02 error in GET /home/summary -> getRecommendations()
- item_enricher: normalizeProductCategory() validates AI-returned category
  against known slugs, falls back to "other" — fixes products_category_fkey
  FK violation during receipt recognition
- recognition prompt: enumerate valid categories so AI returns correct values

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

client/lib/l10n/app_ar.arb

@@ -231,5 +231,7 @@
     }
   },
   "recognitionReplaceProduct": "استبدال المنتج",
-  "scanJobCloseHint": "يمكنك إغلاق التطبيق — سيظهر هذا المسح في عمليات المسح الأخيرة في شاشة المنتجات"
+  "scanJobCloseHint": "يمكنك إغلاق التطبيق — سيظهر هذا المسح في عمليات المسح الأخيرة في شاشة المنتجات",
+  "minimize": "تصغير",
+  "dishRecognitionHint": "يمكنك التصغير — ستظهر النتيجة في الشاشة الرئيسية عند الانتهاء"
 }

client/lib/l10n/app_de.arb

@@ -231,5 +231,7 @@
     }
   },
   "recognitionReplaceProduct": "Produkt ersetzen",
-  "scanJobCloseHint": "Du kannst die App schließen — dieser Scan erscheint in Letzte Scans auf dem Produktbildschirm"
+  "scanJobCloseHint": "Du kannst die App schließen — dieser Scan erscheint in Letzte Scans auf dem Produktbildschirm",
+  "minimize": "Minimieren",
+  "dishRecognitionHint": "Du kannst minimieren — das Ergebnis erscheint auf dem Startbildschirm, wenn fertig"
 }

client/lib/l10n/app_en.arb

@@ -231,5 +231,7 @@
     }
   },
   "recognitionReplaceProduct": "Replace product",
-  "scanJobCloseHint": "You can close the app — this scan will appear in Recent Scans on the Products screen"
+  "scanJobCloseHint": "You can close the app — this scan will appear in Recent Scans on the Products screen",
+  "minimize": "Minimize",
+  "dishRecognitionHint": "You can minimize — the result will appear on the Home screen when done"
 }

client/lib/l10n/app_es.arb

@@ -231,5 +231,7 @@
     }
   },
   "recognitionReplaceProduct": "Reemplazar producto",
-  "scanJobCloseHint": "Puedes cerrar la app — este escaneo aparecerá en Escaneos recientes en la pantalla de Productos"
+  "scanJobCloseHint": "Puedes cerrar la app — este escaneo aparecerá en Escaneos recientes en la pantalla de Productos",
+  "minimize": "Minimizar",
+  "dishRecognitionHint": "Puedes minimizar — el resultado aparecerá en la pantalla principal cuando esté listo"
 }

client/lib/l10n/app_fr.arb

@@ -231,5 +231,7 @@
     }
   },
   "recognitionReplaceProduct": "Remplacer le produit",
-  "scanJobCloseHint": "Vous pouvez fermer l'app — ce scan apparaîtra dans Scans récents sur l'écran Produits"
+  "scanJobCloseHint": "Vous pouvez fermer l'app — ce scan apparaîtra dans Scans récents sur l'écran Produits",
+  "minimize": "Réduire",
+  "dishRecognitionHint": "Vous pouvez réduire — le résultat apparaîtra sur l'écran d'accueil quand c'est terminé"
 }

client/lib/l10n/app_hi.arb

@@ -231,5 +231,7 @@
     }
   },
   "recognitionReplaceProduct": "उत्पाद बदलें",
-  "scanJobCloseHint": "आप ऐप बंद कर सकते हैं — यह स्कैन उत्पाद स्क्रीन पर हाल के स्कैन में दिखाई देगा"
+  "scanJobCloseHint": "आप ऐप बंद कर सकते हैं — यह स्कैन उत्पाद स्क्रीन पर हाल के स्कैन में दिखाई देगा",
+  "minimize": "छोटा करें",
+  "dishRecognitionHint": "आप छोटा कर सकते हैं — पूर्ण होने पर परिणाम होम स्क्रीन पर दिखेगा"
 }

client/lib/l10n/app_it.arb

@@ -231,5 +231,7 @@
     }
   },
   "recognitionReplaceProduct": "Sostituisci prodotto",
-  "scanJobCloseHint": "Puoi chiudere l'app — questa scansione apparirà in Scansioni recenti nella schermata Prodotti"
+  "scanJobCloseHint": "Puoi chiudere l'app — questa scansione apparirà in Scansioni recenti nella schermata Prodotti",
+  "minimize": "Riduci a icona",
+  "dishRecognitionHint": "Puoi ridurre a icona — il risultato apparirà nella schermata principale al termine"
 }

client/lib/l10n/app_ja.arb

@@ -231,5 +231,7 @@
     }
   },
   "recognitionReplaceProduct": "商品を置き換える",
-  "scanJobCloseHint": "アプリを閉じても大丈夫です — このスキャンは製品画面の最近のスキャンに表示されます"
+  "scanJobCloseHint": "アプリを閉じても大丈夫です — このスキャンは製品画面の最近のスキャンに表示されます",
+  "minimize": "最小化",
+  "dishRecognitionHint": "最小化できます — 完了したら結果がホーム画面に表示されます"
 }

client/lib/l10n/app_ko.arb

@@ -231,5 +231,7 @@
     }
   },
   "recognitionReplaceProduct": "제품 교체",
-  "scanJobCloseHint": "앱을 닫아도 됩니다 — 이 스캔은 제품 화면의 최근 스캔에 표시됩니다"
+  "scanJobCloseHint": "앱을 닫아도 됩니다 — 이 스캔은 제품 화면의 최근 스캔에 표시됩니다",
+  "minimize": "최소화",
+  "dishRecognitionHint": "최소화할 수 있습니다 — 완료되면 홈 화면에 결과가 표시됩니다"
 }

client/lib/l10n/app_localizations.dart

@@ -1215,6 +1215,18 @@ abstract class AppLocalizations {
   /// In en, this message translates to:
   /// **'You can close the app — this scan will appear in Recent Scans on the Products screen'**
   String get scanJobCloseHint;
+
+  /// No description provided for @minimize.
+  ///
+  /// In en, this message translates to:
+  /// **'Minimize'**
+  String get minimize;
+
+  /// No description provided for @dishRecognitionHint.
+  ///
+  /// In en, this message translates to:
+  /// **'You can minimize — the result will appear on the Home screen when done'**
+  String get dishRecognitionHint;
 }
 
 class _AppLocalizationsDelegate

client/lib/l10n/app_localizations_ar.dart

@@ -575,4 +575,11 @@ class AppLocalizationsAr extends AppLocalizations {
   @override
   String get scanJobCloseHint =>
       'يمكنك إغلاق التطبيق — سيظهر هذا المسح في عمليات المسح الأخيرة في شاشة المنتجات';
+
+  @override
+  String get minimize => 'تصغير';
+
+  @override
+  String get dishRecognitionHint =>
+      'يمكنك التصغير — ستظهر النتيجة في الشاشة الرئيسية عند الانتهاء';
 }

client/lib/l10n/app_localizations_de.dart

@@ -579,4 +579,11 @@ class AppLocalizationsDe extends AppLocalizations {
   @override
   String get scanJobCloseHint =>
       'Du kannst die App schließen — dieser Scan erscheint in Letzte Scans auf dem Produktbildschirm';
+
+  @override
+  String get minimize => 'Minimieren';
+
+  @override
+  String get dishRecognitionHint =>
+      'Du kannst minimieren — das Ergebnis erscheint auf dem Startbildschirm, wenn fertig';
 }

client/lib/l10n/app_localizations_en.dart

@@ -577,4 +577,11 @@ class AppLocalizationsEn extends AppLocalizations {
   @override
   String get scanJobCloseHint =>
       'You can close the app — this scan will appear in Recent Scans on the Products screen';
+
+  @override
+  String get minimize => 'Minimize';
+
+  @override
+  String get dishRecognitionHint =>
+      'You can minimize — the result will appear on the Home screen when done';
 }

client/lib/l10n/app_localizations_es.dart

@@ -580,4 +580,11 @@ class AppLocalizationsEs extends AppLocalizations {
   @override
   String get scanJobCloseHint =>
       'Puedes cerrar la app — este escaneo aparecerá en Escaneos recientes en la pantalla de Productos';
+
+  @override
+  String get minimize => 'Minimizar';
+
+  @override
+  String get dishRecognitionHint =>
+      'Puedes minimizar — el resultado aparecerá en la pantalla principal cuando esté listo';
 }

client/lib/l10n/app_localizations_fr.dart

@@ -580,4 +580,11 @@ class AppLocalizationsFr extends AppLocalizations {
   @override
   String get scanJobCloseHint =>
       'Vous pouvez fermer l\'app — ce scan apparaîtra dans Scans récents sur l\'écran Produits';
+
+  @override
+  String get minimize => 'Réduire';
+
+  @override
+  String get dishRecognitionHint =>
+      'Vous pouvez réduire — le résultat apparaîtra sur l\'écran d\'accueil quand c\'est terminé';
 }

client/lib/l10n/app_localizations_hi.dart

@@ -578,4 +578,11 @@ class AppLocalizationsHi extends AppLocalizations {
   @override
   String get scanJobCloseHint =>
       'आप ऐप बंद कर सकते हैं — यह स्कैन उत्पाद स्क्रीन पर हाल के स्कैन में दिखाई देगा';
+
+  @override
+  String get minimize => 'छोटा करें';
+
+  @override
+  String get dishRecognitionHint =>
+      'आप छोटा कर सकते हैं — पूर्ण होने पर परिणाम होम स्क्रीन पर दिखेगा';
 }

client/lib/l10n/app_localizations_it.dart

@@ -580,4 +580,11 @@ class AppLocalizationsIt extends AppLocalizations {
   @override
   String get scanJobCloseHint =>
       'Puoi chiudere l\'app — questa scansione apparirà in Scansioni recenti nella schermata Prodotti';
+
+  @override
+  String get minimize => 'Riduci a icona';
+
+  @override
+  String get dishRecognitionHint =>
+      'Puoi ridurre a icona — il risultato apparirà nella schermata principale al termine';
 }

client/lib/l10n/app_localizations_ja.dart

@@ -571,4 +571,10 @@ class AppLocalizationsJa extends AppLocalizations {
 
   @override
   String get scanJobCloseHint => 'アプリを閉じても大丈夫です — このスキャンは製品画面の最近のスキャンに表示されます';
+
+  @override
+  String get minimize => '最小化';
+
+  @override
+  String get dishRecognitionHint => '最小化できます — 完了したら結果がホーム画面に表示されます';
 }

client/lib/l10n/app_localizations_ko.dart

@@ -571,4 +571,10 @@ class AppLocalizationsKo extends AppLocalizations {
 
   @override
   String get scanJobCloseHint => '앱을 닫아도 됩니다 — 이 스캔은 제품 화면의 최근 스캔에 표시됩니다';
+
+  @override
+  String get minimize => '최소화';
+
+  @override
+  String get dishRecognitionHint => '최소화할 수 있습니다 — 완료되면 홈 화면에 결과가 표시됩니다';
 }

client/lib/l10n/app_localizations_pt.dart

@@ -579,4 +579,11 @@ class AppLocalizationsPt extends AppLocalizations {
   @override
   String get scanJobCloseHint =>
       'Você pode fechar o app — este scan aparecerá em Scans recentes na tela de Produtos';
+
+  @override
+  String get minimize => 'Minimizar';
+
+  @override
+  String get dishRecognitionHint =>
+      'Você pode minimizar — o resultado aparecerá na tela inicial quando concluído';
 }

client/lib/l10n/app_localizations_ru.dart

@@ -578,4 +578,11 @@ class AppLocalizationsRu extends AppLocalizations {
   @override
   String get scanJobCloseHint =>
       'Можно закрыть приложение — скан появится в последних сканированиях на экране продуктов';
+
+  @override
+  String get minimize => 'Свернуть';
+
+  @override
+  String get dishRecognitionHint =>
+      'Можно свернуть — результат появится на главном экране по завершении';
 }

client/lib/l10n/app_localizations_zh.dart

@@ -570,4 +570,10 @@ class AppLocalizationsZh extends AppLocalizations {
 
   @override
   String get scanJobCloseHint => '您可以关闭应用 — 此扫描将显示在产品页面的最近扫描中';
+
+  @override
+  String get minimize => '最小化';
+
+  @override
+  String get dishRecognitionHint => '可以最小化 — 完成后结果将显示在主屏幕上';
 }

client/lib/l10n/app_pt.arb

@@ -231,5 +231,7 @@
     }
   },
   "recognitionReplaceProduct": "Substituir produto",
-  "scanJobCloseHint": "Você pode fechar o app — este scan aparecerá em Scans recentes na tela de Produtos"
+  "scanJobCloseHint": "Você pode fechar o app — este scan aparecerá em Scans recentes na tela de Produtos",
+  "minimize": "Minimizar",
+  "dishRecognitionHint": "Você pode minimizar — o resultado aparecerá na tela inicial quando concluído"
 }

client/lib/l10n/app_ru.arb

@@ -231,5 +231,7 @@
     }
   },
   "recognitionReplaceProduct": "Заменить продукт",
-  "scanJobCloseHint": "Можно закрыть приложение — скан появится в последних сканированиях на экране продуктов"
+  "scanJobCloseHint": "Можно закрыть приложение — скан появится в последних сканированиях на экране продуктов",
+  "minimize": "Свернуть",
+  "dishRecognitionHint": "Можно свернуть — результат появится на главном экране по завершении"
 }

client/lib/l10n/app_zh.arb

@@ -231,5 +231,7 @@
     }
   },
   "recognitionReplaceProduct": "替换产品",
-  "scanJobCloseHint": "您可以关闭应用 — 此扫描将显示在产品页面的最近扫描中"
+  "scanJobCloseHint": "您可以关闭应用 — 此扫描将显示在产品页面的最近扫描中",
+  "minimize": "最小化",
+  "dishRecognitionHint": "可以最小化 — 完成后结果将显示在主屏幕上"
 }