refactor: complete JS i18n migration for confirm dialogs and toast messages

Migrate 34 hardcoded user-facing strings to use I18n.t() for translation:

- CMS: media file operations (5 strings)
- Marketplace: Letzshop integration (16 strings)
- Messaging: notifications, messages, email templates (5 strings)
- Tenancy: platform modules, menu config, theme (5 strings)
- Core: menu config, settings, storefront cart (5 strings)
- Catalog: product creation (3 strings)
- Utils: clipboard operations (2 strings)

Added confirmations and messages keys to module locale files.
Added I18n.loadModule() calls to JS files that were missing them.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

app/modules/core/locales/en.json

@@ -0,0 +1,79 @@
+{
+  "dashboard": {
+    "title": "Dashboard",
+    "welcome": "Welcome back",
+    "overview": "Overview",
+    "quick_stats": "Quick Stats",
+    "recent_activity": "Recent Activity",
+    "total_products": "Total Products",
+    "total_orders": "Total Orders",
+    "total_customers": "Total Customers",
+    "total_revenue": "Total Revenue",
+    "active_products": "Active Products",
+    "pending_orders": "Pending Orders",
+    "new_customers": "New Customers",
+    "today": "Today",
+    "this_week": "This Week",
+    "this_month": "This Month",
+    "this_year": "This Year",
+    "error_loading": "Error loading dashboard",
+    "no_data": "No data available"
+  },
+  "settings": {
+    "title": "Settings",
+    "general": "General",
+    "store": "Store",
+    "store_name": "Store Name",
+    "store_description": "Store Description",
+    "contact_email": "Contact Email",
+    "contact_phone": "Contact Phone",
+    "business_address": "Business Address",
+    "tax_number": "Tax Number",
+    "currency": "Currency",
+    "timezone": "Timezone",
+    "language": "Language",
+    "language_settings": "Language Settings",
+    "default_language": "Default Language",
+    "dashboard_language": "Dashboard Language",
+    "storefront_language": "Storefront Language",
+    "enabled_languages": "Enabled Languages",
+    "notifications": "Notifications",
+    "email_notifications": "Email Notifications",
+    "integrations": "Integrations",
+    "api_keys": "API Keys",
+    "webhooks": "Webhooks",
+    "save_settings": "Save Settings",
+    "settings_saved": "Settings saved successfully"
+  },
+  "profile": {
+    "title": "Profile",
+    "my_profile": "My Profile",
+    "edit_profile": "Edit Profile",
+    "personal_info": "Personal Information",
+    "first_name": "First Name",
+    "last_name": "Last Name",
+    "email": "Email",
+    "phone": "Phone",
+    "avatar": "Avatar",
+    "change_avatar": "Change Avatar",
+    "security": "Security",
+    "two_factor": "Two-Factor Authentication",
+    "sessions": "Active Sessions",
+    "preferences": "Preferences",
+    "language_preference": "Language Preference",
+    "save_profile": "Save Profile",
+    "profile_updated": "Profile updated successfully"
+  },
+  "messages": {
+    "failed_to_load_dashboard_data": "Failed to load dashboard data",
+    "dashboard_refreshed": "Dashboard refreshed",
+    "item_removed_from_cart": "Item removed from cart",
+    "cart_cleared": "Cart cleared"
+  },
+  "confirmations": {
+    "show_all_menu_items": "This will show all menu items. Continue?",
+    "hide_all_menu_items": "This will hide all menu items (except mandatory ones). You can then enable the ones you want. Continue?",
+    "reset_email_settings": "This will reset all email settings to use .env defaults. Continue?",
+    "cleanup_logs": "This will delete all logs older than {days} days. Continue?"
+  }
+}