feat: multi-module improvements across merchant, store, i18n, and customer systems

- Fix platform-grouped merchant sidebar menu with core items at root level
- Add merchant store management (detail page, create store, team page)
- Fix store settings 500 error by removing dead stripe/API tab
- Move onboarding translations to module-owned locale files
- Fix onboarding banner i18n with server-side rendering + context inheritance
- Refactor login language selectors to use languageSelector() function (LANG-002)
- Move HTTPException handling to global exception handler in merchant routes (API-003)
- Add language selector to all login pages and portal headers
- Fix customer module: drop order stats from customer model, add to orders module
- Fix admin menu config visibility for super admin platform context
- Fix storefront auth and layout issues
- Add missing i18n translations for onboarding steps (en/fr/de/lb)

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

app/modules/customers/tests/unit/test_admin_customer_service.py

@@ -3,8 +3,6 @@
 Unit tests for AdminCustomerService.
 """
 
-from decimal import Decimal
-
 import pytest
 
 from app.modules.customers.exceptions import CustomerNotFoundException
@@ -18,16 +16,6 @@ def admin_customer_service():
     return AdminCustomerService()
 
 
-@pytest.fixture
-def customer_with_orders(db, test_store, test_customer):
-    """Create a customer with order data."""
-    test_customer.total_orders = 5
-    test_customer.total_spent = Decimal("250.00")
-    db.commit()
-    db.refresh(test_customer)
-    return test_customer
-
-
 @pytest.fixture
 def multiple_customers(db, test_store):
     """Create multiple customers for testing."""
@@ -41,8 +29,6 @@ def multiple_customers(db, test_store):
             last_name=f"Last{i}",
             customer_number=f"CUST-00{i}",
             is_active=(i % 2 == 0),  # Alternate active/inactive
-            total_orders=i,
-            total_spent=Decimal(str(i * 100)),
         )
         db.add(customer)  # noqa: PERF006
         customers.append(customer)
@@ -165,10 +151,6 @@ class TestAdminCustomerServiceStats:
         assert stats["total"] == 0
         assert stats["active"] == 0
         assert stats["inactive"] == 0
-        assert stats["with_orders"] == 0
-        assert stats["total_spent"] == 0
-        assert stats["total_orders"] == 0
-        assert stats["avg_order_value"] == 0
 
     def test_get_customer_stats_with_data(
         self, db, admin_customer_service, multiple_customers
@@ -179,12 +161,6 @@ class TestAdminCustomerServiceStats:
         assert stats["total"] == 5
         assert stats["active"] == 3  # 0, 2, 4
         assert stats["inactive"] == 2  # 1, 3
-        # with_orders = customers with total_orders > 0 (1, 2, 3, 4 = 4 customers)
-        assert stats["with_orders"] == 4
-        # total_spent = 0 + 100 + 200 + 300 + 400 = 1000
-        assert stats["total_spent"] == 1000.0
-        # total_orders = 0 + 1 + 2 + 3 + 4 = 10
-        assert stats["total_orders"] == 10
 
     def test_get_customer_stats_by_store(
         self, db, admin_customer_service, test_customer, test_store
@@ -194,16 +170,6 @@ class TestAdminCustomerServiceStats:
 
         assert stats["total"] == 1
 
-    def test_get_customer_stats_avg_order_value(
-        self, db, admin_customer_service, customer_with_orders
-    ):
-        """Test average order value calculation."""
-        stats = admin_customer_service.get_customer_stats(db)
-
-        # total_spent = 250, total_orders = 5
-        # avg = 250 / 5 = 50
-        assert stats["avg_order_value"] == 50.0
-
 
 @pytest.mark.unit
 class TestAdminCustomerServiceGetCustomer:

app/modules/customers/tests/unit/test_customer_model.py

@@ -49,8 +49,6 @@ class TestCustomerModel:
 
         assert customer.is_active is True  # Default
         assert customer.marketing_consent is False  # Default
-        assert customer.total_orders == 0  # Default
-        assert customer.total_spent == 0  # Default
 
     def test_customer_full_name_property(self, db, test_store):
         """Test Customer full_name computed property."""

app/modules/customers/tests/unit/test_customer_schema.py

@@ -149,7 +149,6 @@ class TestCustomerResponseSchema:
     def test_from_dict(self):
         """Test creating response from dict."""
         from datetime import datetime
-        from decimal import Decimal
 
         data = {
             "id": 1,
@@ -161,9 +160,6 @@ class TestCustomerResponseSchema:
             "customer_number": "CUST001",
             "marketing_consent": False,
             "preferred_language": "fr",
-            "last_order_date": None,
-            "total_orders": 5,
-            "total_spent": Decimal("500.00"),
             "is_active": True,
             "created_at": datetime.now(),
             "updated_at": datetime.now(),
@@ -171,7 +167,7 @@ class TestCustomerResponseSchema:
         response = CustomerResponse(**data)
         assert response.id == 1
         assert response.customer_number == "CUST001"
-        assert response.total_orders == 5
+        assert response.preferred_language == "fr"
 
 
 @pytest.mark.unit