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/templates/tenancy/admin/platform-edit.html

@@ -130,19 +130,41 @@
                     <span x-show="errors.name" class="text-xs text-red-600 dark:text-red-400 mt-1" x-text="errors.name"></span>
                 </label>
 
-                <!-- Description -->
-                <label class="block mb-4 text-sm">
+                <!-- Description (multilingual) -->
+                <div class="block mb-4 text-sm">
                     <span class="text-gray-700 dark:text-gray-400">
                         Description
                     </span>
+
+                    <!-- Language Tabs -->
+                    <div class="mt-2 border-b border-gray-200 dark:border-gray-700">
+                        <nav class="flex -mb-px space-x-2">
+                            <template x-for="lang in formData.supported_languages" :key="lang">
+                                <button
+                                    type="button"
+                                    @click="currentLang = lang"
+                                    :class="currentLang === lang
+                                        ? 'border-purple-500 text-purple-600 dark:text-purple-400'
+                                        : 'border-transparent text-gray-500 dark:text-gray-400 hover:text-gray-700 dark:hover:text-gray-300'"
+                                    class="py-2 px-3 border-b-2 font-medium text-xs transition-colors"
+                                >
+                                    <span x-text="languageNames[lang] || lang.toUpperCase()"></span>
+                                    <span x-show="lang === formData.default_language" class="ml-1 text-xs text-gray-400">(default)</span>
+                                </button>
+                            </template>
+                        </nav>
+                    </div>
+
+                    <!-- Per-language textarea -->
                     <textarea
-                        x-model="formData.description"
+                        x-model="formData.description_translations[currentLang]"
                         rows="3"
                         maxlength="500"
                         :disabled="saving"
-                        class="block w-full mt-1 text-sm dark:text-gray-300 dark:border-gray-600 dark:bg-gray-700 focus:border-purple-400 focus:outline-none focus:shadow-outline-purple dark:focus:shadow-outline-gray form-textarea"
+                        :placeholder="'Description in ' + (languageNames[currentLang] || currentLang)"
+                        class="block w-full mt-2 text-sm dark:text-gray-300 dark:border-gray-600 dark:bg-gray-700 focus:border-purple-400 focus:outline-none focus:shadow-outline-purple dark:focus:shadow-outline-gray form-textarea"
                     ></textarea>
-                </label>
+                </div>
 
                 <!-- Default Language -->
                 <label class="block mb-4 text-sm">