feat(i18n): add multilingual platform descriptions and HostWizard demo data

- Add description_translations JSON column to Platform model + migration
- Add language tabs to platform admin edit form for multilingual descriptions
- Update API schemas to include description_translations in request/response
- Translate pricing section UI labels via _t() macro (monthly/annual/CTA/etc.)
- Add Luxembourgish (lb) support to all platforms (OMS, Main, Loyalty, Hosting)
- Seed description_translations, contact emails, and social links for all platforms
- Add LuxWeb Agency demo merchant with hosting stores, team, and content pages
- Fix language code typo: lu → lb in platform-edit.js availableLanguages
- Fix store content pages to use correct primary platform instead of hardcoded OMS

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

app/modules/tenancy/static/admin/js/platform-edit.js

@@ -22,10 +22,20 @@ function platformEdit() {
     success: null,
     platformCode: null,
 
+    // Language editing
+    currentLang: 'fr',
+    languageNames: {
+      fr: 'Fran\u00e7ais',
+      de: 'Deutsch',
+      en: 'English',
+      lb: 'L\u00ebtzebuergesch',
+    },
+
     // Form data
     formData: {
       name: '',
       description: '',
+      description_translations: {},
       domain: '',
       path_prefix: '',
       logo: '',
@@ -46,7 +56,7 @@ function platformEdit() {
       { code: 'fr', name: 'French' },
       { code: 'de', name: 'German' },
       { code: 'en', name: 'English' },
-      { code: 'lu', name: 'Luxembourgish' },
+      { code: 'lb', name: 'Luxembourgish' },
     ],
 
     // Lifecycle
@@ -92,23 +102,34 @@ function platformEdit() {
         const response = await apiClient.get(`/admin/platforms/${this.platformCode}`);
         this.platform = response;
 
+        // Build description_translations with empty strings for all supported languages
+        const langs = response.supported_languages || ['fr', 'de', 'en'];
+        const descTranslations = {};
+        for (const lang of langs) {
+          descTranslations[lang] = (response.description_translations && response.description_translations[lang]) || '';
+        }
+
         // Populate form data
         this.formData = {
           name: response.name || '',
           description: response.description || '',
+          description_translations: descTranslations,
           domain: response.domain || '',
           path_prefix: response.path_prefix || '',
           logo: response.logo || '',
           logo_dark: response.logo_dark || '',
           favicon: response.favicon || '',
           default_language: response.default_language || 'fr',
-          supported_languages: response.supported_languages || ['fr', 'de', 'en'],
+          supported_languages: langs,
           is_active: response.is_active ?? true,
           is_public: response.is_public ?? true,
           theme_config: response.theme_config || {},
           settings: response.settings || {},
         };
 
+        // Set current language tab to default language
+        this.currentLang = response.default_language || 'fr';
+
         platformEditLog.info(`Loaded platform: ${this.platformCode}`);
       } catch (err) {
         platformEditLog.error('Error loading platform:', err);
@@ -126,9 +147,14 @@ function platformEdit() {
 
       try {
         // Build update payload (only changed fields)
+        // Sync base description from default language translation
+        const defaultLang = this.formData.default_language || 'fr';
+        const baseDesc = this.formData.description_translations[defaultLang] || this.formData.description;
+
         const payload = {
           name: this.formData.name,
-          description: this.formData.description || null,
+          description: baseDesc || null,
+          description_translations: this.formData.description_translations,
           domain: this.formData.domain || null,
           path_prefix: this.formData.path_prefix || null,
           logo: this.formData.logo || null,
@@ -199,9 +225,17 @@ function platformEdit() {
         // Don't allow removing the last language
         if (this.formData.supported_languages.length > 1) {
           this.formData.supported_languages.splice(index, 1);
+          // Switch tab if the removed language was active
+          if (this.currentLang === code) {
+            this.currentLang = this.formData.supported_languages[0];
+          }
         }
       } else {
         this.formData.supported_languages.push(code);
+        // Initialize empty translation for new language
+        if (!this.formData.description_translations[code]) {
+          this.formData.description_translations[code] = '';
+        }
       }
     },