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/cart/definition.py

@@ -68,7 +68,7 @@ cart_module = ModuleDefinition(
                 items=[
                     MenuItemDefinition(
                         id="cart",
-                        label_key="storefront.actions.cart",
+                        label_key="cart.storefront.actions.cart",
                         icon="shopping-cart",
                         route="cart",
                         order=20,

app/modules/cart/locales/de.json

@@ -44,5 +44,10 @@
         "view_desc": "Warenkörbe der Kunden anzeigen",
         "manage": "Warenkörbe verwalten",
         "manage_desc": "Warenkörbe der Kunden bearbeiten und verwalten"
+    },
+    "storefront": {
+        "actions": {
+            "cart": "Warenkorb"
+        }
     }
 }

app/modules/cart/locales/en.json

@@ -1,48 +1,53 @@
 {
-  "title": "Shopping Cart",
-  "description": "Shopping cart management for customers",
-  "cart": {
-    "title": "Your Cart",
-    "empty": "Your cart is empty",
-    "empty_subtitle": "Add items to start shopping",
-    "continue_shopping": "Continue Shopping",
-    "proceed_to_checkout": "Proceed to Checkout"
-  },
-  "item": {
-    "product": "Product",
-    "quantity": "Quantity",
-    "price": "Price",
-    "total": "Total",
-    "remove": "Remove",
-    "update": "Update"
-  },
-  "summary": {
-    "title": "Order Summary",
-    "subtotal": "Subtotal",
-    "shipping": "Shipping",
-    "estimated_shipping": "Calculated at checkout",
-    "tax": "Tax",
-    "total": "Total"
-  },
-  "validation": {
-    "invalid_quantity": "Invalid quantity",
-    "min_quantity": "Minimum quantity is {min}",
-    "max_quantity": "Maximum quantity is {max}",
-    "insufficient_inventory": "Only {available} available"
-  },
-  "permissions": {
-    "view": "View Carts",
-    "view_desc": "View customer shopping carts",
-    "manage": "Manage Carts",
-    "manage_desc": "Modify and manage customer carts"
-  },
-  "messages": {
-    "item_added": "Item added to cart",
-    "item_updated": "Cart updated",
-    "item_removed": "Item removed from cart",
-    "cart_cleared": "Cart cleared",
-    "product_not_available": "Product not available",
-    "error_adding": "Error adding item to cart",
-    "error_updating": "Error updating cart"
-  }
+    "title": "Shopping Cart",
+    "description": "Shopping cart management for customers",
+    "cart": {
+        "title": "Your Cart",
+        "empty": "Your cart is empty",
+        "empty_subtitle": "Add items to start shopping",
+        "continue_shopping": "Continue Shopping",
+        "proceed_to_checkout": "Proceed to Checkout"
+    },
+    "item": {
+        "product": "Product",
+        "quantity": "Quantity",
+        "price": "Price",
+        "total": "Total",
+        "remove": "Remove",
+        "update": "Update"
+    },
+    "summary": {
+        "title": "Order Summary",
+        "subtotal": "Subtotal",
+        "shipping": "Shipping",
+        "estimated_shipping": "Calculated at checkout",
+        "tax": "Tax",
+        "total": "Total"
+    },
+    "validation": {
+        "invalid_quantity": "Invalid quantity",
+        "min_quantity": "Minimum quantity is {min}",
+        "max_quantity": "Maximum quantity is {max}",
+        "insufficient_inventory": "Only {available} available"
+    },
+    "permissions": {
+        "view": "View Carts",
+        "view_desc": "View customer shopping carts",
+        "manage": "Manage Carts",
+        "manage_desc": "Modify and manage customer carts"
+    },
+    "messages": {
+        "item_added": "Item added to cart",
+        "item_updated": "Cart updated",
+        "item_removed": "Item removed from cart",
+        "cart_cleared": "Cart cleared",
+        "product_not_available": "Product not available",
+        "error_adding": "Error adding item to cart",
+        "error_updating": "Error updating cart"
+    },
+    "storefront": {
+        "actions": {
+            "cart": "Cart"
+        }
+    }
 }

app/modules/cart/locales/fr.json

@@ -44,5 +44,10 @@
         "view_desc": "Voir les paniers des clients",
         "manage": "Gérer les paniers",
         "manage_desc": "Modifier et gérer les paniers des clients"
+    },
+    "storefront": {
+        "actions": {
+            "cart": "Panier"
+        }
     }
 }

app/modules/cart/locales/lb.json

@@ -44,5 +44,10 @@
         "view_desc": "Clientekuerf kucken",
         "manage": "Kuerf verwalten",
         "manage_desc": "Clientekuerf änneren a verwalten"
+    },
+    "storefront": {
+        "actions": {
+            "cart": "Kuerf"
+        }
     }
 }