fix: Add missing 'reasoning' namespace to i18n configuration

CRITICAL FIX: Translation keys showing instead of translated text

The Bug:
--------
Dashboard components were using useTranslation('reasoning') but the
'reasoning' namespace was NOT loaded into i18n configuration.

Result: i18n couldn't find translations and returned keys literally:
- "jtbd.health_status.last_updated" instead of "Last updated" / "Última actualización"
- "jtbd.action_queue.all_caught_up" instead of "All caught up!" / "¡Todo al día!"
- "jtbd.production_timeline.no_production" instead of translations
- etc.

Why It Happened:
----------------
locales/index.ts was missing:
1. Import statements for reasoning.json (all 3 languages)
2. 'reasoning' property in resources object (es/en/eu)
3. 'reasoning' in namespaces array

The Fix:
--------
Added to frontend/src/locales/index.ts:

1. Imports:
   import reasoningEs from './es/reasoning.json';
   import reasoningEn from './en/reasoning.json';
   import reasoningEu from './eu/reasoning.json';

2. Resources object:
   es: { ..., reasoning: reasoningEs }
   en: { ..., reasoning: reasoningEn }
   eu: { ..., reasoning: reasoningEu }

3. Namespaces array:
   export const namespaces = [..., 'reasoning'] as const;

4. Exports:
   export { ..., reasoningEs };

Now:
----
✅ t('jtbd.health_status.last_updated') returns "Last updated" (en) or "Última actualización" (es)
✅ All dashboard translations work in all 3 languages (es, en, eu)
✅ Language switching works properly

frontend/src/locales/index.ts

@@ -13,6 +13,7 @@ import equipmentEs from './es/equipment.json';
 import landingEs from './es/landing.json';
 import settingsEs from './es/settings.json';
 import ajustesEs from './es/ajustes.json';
+import reasoningEs from './es/reasoning.json';
 
 // English translations
 import commonEn from './en/common.json';
@@ -29,6 +30,7 @@ import equipmentEn from './en/equipment.json';
 import landingEn from './en/landing.json';
 import settingsEn from './en/settings.json';
 import ajustesEn from './en/ajustes.json';
+import reasoningEn from './en/reasoning.json';
 
 // Basque translations
 import commonEu from './eu/common.json';
@@ -45,6 +47,7 @@ import equipmentEu from './eu/equipment.json';
 import landingEu from './eu/landing.json';
 import settingsEu from './eu/settings.json';
 import ajustesEu from './eu/ajustes.json';
+import reasoningEu from './eu/reasoning.json';
 
 // Translation resources by language
 export const resources = {
@@ -63,6 +66,7 @@ export const resources = {
     landing: landingEs,
     settings: settingsEs,
     ajustes: ajustesEs,
+    reasoning: reasoningEs,
   },
   en: {
     common: commonEn,
@@ -79,6 +83,7 @@ export const resources = {
     landing: landingEn,
     settings: settingsEn,
     ajustes: ajustesEn,
+    reasoning: reasoningEn,
   },
   eu: {
     common: commonEu,
@@ -95,6 +100,7 @@ export const resources = {
     landing: landingEu,
     settings: settingsEu,
     ajustes: ajustesEu,
+    reasoning: reasoningEu,
   },
 };
 
@@ -131,7 +137,7 @@ export const languageConfig = {
 };
 
 // Namespaces available in translations
-export const namespaces = ['common', 'auth', 'inventory', 'foodSafety', 'suppliers', 'orders', 'recipes', 'errors', 'dashboard', 'production', 'equipment', 'landing', 'settings', 'ajustes'] as const;
+export const namespaces = ['common', 'auth', 'inventory', 'foodSafety', 'suppliers', 'orders', 'recipes', 'errors', 'dashboard', 'production', 'equipment', 'landing', 'settings', 'ajustes', 'reasoning'] as const;
 export type Namespace = typeof namespaces[number];
 
 // Helper function to get language display name
@@ -145,7 +151,7 @@ export const isSupportedLanguage = (language: string): language is SupportedLang
 };
 
 // Export individual language modules for direct imports
-export { commonEs, authEs, inventoryEs, foodSafetyEs, suppliersEs, ordersEs, recipesEs, errorsEs, equipmentEs, landingEs, settingsEs, ajustesEs };
+export { commonEs, authEs, inventoryEs, foodSafetyEs, suppliersEs, ordersEs, recipesEs, errorsEs, equipmentEs, landingEs, settingsEs, ajustesEs, reasoningEs };
 
 // Default export with all translations
 export default resources;