feat(storefront): homepage, module gating, widget protocol, i18n fixes

Storefront homepage & module gating:
- CMS owns storefront GET / (slug="home" with 3-tier resolution)
- Catalog loses GET / (keeps /products only)
- Store root redirect (GET / → /store/dashboard or /store/login)
- Route gating: non-core modules return 404 when disabled for platform
- Seed store default homepages per platform

Widget protocol for customer dashboard:
- StorefrontDashboardCard contract in widgets.py
- Widget aggregator get_storefront_dashboard_cards()
- Orders and Loyalty module widget providers
- Dashboard template renders contributed cards (no module names)

Landing template module-agnostic:
- CTAs driven by storefront_nav (not hardcoded module names)
- Header actions check nav item IDs (not enabled_modules)
- Remove hardcoded "Add Product" sidebar button
- Remove all enabled_modules checks from storefront templates

i18n fixes:
- Title placeholder resolution ({{store_name}}) for store default pages
- Storefront nav label_keys prefixed with module code
- Add storefront.account.* keys to 6 modules (en/fr/de/lb)
- Header/footer CMS pages use get_translated_title(current_language)
- Footer labels use i18n keys instead of hardcoded English

Icon cleanup:
- Standardize on map-pin (remove location-marker alias)
- Replace all location-marker references across templates and docs

Docs:
- Storefront builder vision proposal (6 phases)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

app/modules/customers/routes/pages/storefront.py

@@ -195,9 +195,25 @@ async def shop_account_dashboard_page(
         },
     )
 
+    # Collect dashboard cards from enabled modules via widget protocol
+    from app.modules.core.services.widget_aggregator import widget_aggregator
+
+    store = getattr(request.state, "store", None)
+    platform = getattr(request.state, "platform", None)
+    dashboard_cards = []
+    if store and platform:
+        dashboard_cards = widget_aggregator.get_storefront_dashboard_cards(
+            db,
+            store_id=store.id,
+            customer_id=current_customer.id,
+            platform_id=platform.id,
+        )
+
     return templates.TemplateResponse(
         "customers/storefront/dashboard.html",
-        get_storefront_context(request, db=db, user=current_customer),
+        get_storefront_context(
+            request, db=db, user=current_customer, dashboard_cards=dashboard_cards
+        ),
     )