feat: dynamic merchant sidebar with module-driven menus

Replace the hardcoded merchant sidebar with a dynamic menu system driven
by module definitions, matching the existing admin frontend pattern.
Modules declare FrontendType.MERCHANT menus in their definition.py, and
a new API endpoint unions enabled modules across all platforms the
merchant is subscribed to — so loyalty only appears when enabled.

- Add MERCHANT menu definitions to core, billing, tenancy, loyalty modules
- Extend MenuDiscoveryService with enabled_module_codes parameter
- Create GET /merchants/core/menu/render/merchant endpoint
- Update merchant Alpine.js with loadMenuConfig() and dynamic section state
- Replace hardcoded sidebar.html with x-for rendering + loading skeleton + fallback
- Add 36 unit and integration tests for menu discovery, service, and endpoint

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

app/modules/core/tests/unit/test_menu_discovery_service.py

@@ -3,6 +3,7 @@
 import pytest
 
 from app.modules.core.services.menu_discovery_service import MenuDiscoveryService
+from app.modules.enums import FrontendType
 
 
 @pytest.mark.unit
@@ -16,3 +17,165 @@ class TestMenuDiscoveryService:
     def test_service_instantiation(self):
         """Service can be instantiated."""
         assert self.service is not None
+
+    def test_discover_all_menus_includes_merchant(self):
+        """discover_all_menus() includes FrontendType.MERCHANT entries."""
+        menus = self.service.discover_all_menus()
+        assert FrontendType.MERCHANT in menus
+        merchant_sections = menus[FrontendType.MERCHANT]
+        assert len(merchant_sections) > 0, "Expected at least one MERCHANT menu section"
+
+    def test_merchant_menu_has_expected_section_ids(self):
+        """MERCHANT menus contain main, billing, account, and loyalty sections."""
+        menus = self.service.discover_all_menus()
+        section_ids = {s.id for s in menus[FrontendType.MERCHANT]}
+        assert "main" in section_ids
+        assert "billing" in section_ids
+        assert "account" in section_ids
+        assert "loyalty" in section_ids
+
+    def test_merchant_main_section_has_dashboard(self):
+        """Main section contains the dashboard item."""
+        menus = self.service.discover_all_menus()
+        main_sections = [s for s in menus[FrontendType.MERCHANT] if s.id == "main"]
+        assert len(main_sections) == 1
+        item_ids = [i.id for i in main_sections[0].items]
+        assert "dashboard" in item_ids
+
+    def test_merchant_billing_section_items(self):
+        """Billing section contains subscriptions and invoices."""
+        menus = self.service.discover_all_menus()
+        billing_sections = [s for s in menus[FrontendType.MERCHANT] if s.id == "billing"]
+        assert len(billing_sections) == 1
+        item_ids = [i.id for i in billing_sections[0].items]
+        assert "subscriptions" in item_ids
+        assert "invoices" in item_ids
+
+    def test_merchant_account_section_items(self):
+        """Account section contains stores and profile."""
+        menus = self.service.discover_all_menus()
+        account_sections = [s for s in menus[FrontendType.MERCHANT] if s.id == "account"]
+        assert len(account_sections) == 1
+        item_ids = [i.id for i in account_sections[0].items]
+        assert "stores" in item_ids
+        assert "profile" in item_ids
+
+    def test_merchant_loyalty_section_items(self):
+        """Loyalty section contains loyalty-overview."""
+        menus = self.service.discover_all_menus()
+        loyalty_sections = [s for s in menus[FrontendType.MERCHANT] if s.id == "loyalty"]
+        assert len(loyalty_sections) == 1
+        item_ids = [i.id for i in loyalty_sections[0].items]
+        assert "loyalty-overview" in item_ids
+
+    def test_get_all_menu_items_merchant(self):
+        """get_all_menu_items returns items for MERCHANT frontend type."""
+        items = self.service.get_all_menu_items(FrontendType.MERCHANT)
+        assert len(items) > 0
+        item_ids = {i.id for i in items}
+        assert "dashboard" in item_ids
+        assert "subscriptions" in item_ids
+        assert "loyalty-overview" in item_ids
+
+    def test_get_all_menu_item_ids_merchant(self):
+        """get_all_menu_item_ids returns IDs for MERCHANT frontend type."""
+        item_ids = self.service.get_all_menu_item_ids(FrontendType.MERCHANT)
+        assert "dashboard" in item_ids
+        assert "subscriptions" in item_ids
+        assert "invoices" in item_ids
+        assert "stores" in item_ids
+        assert "profile" in item_ids
+        assert "loyalty-overview" in item_ids
+
+    def test_get_mandatory_item_ids_merchant(self):
+        """Mandatory items for MERCHANT include dashboard and subscriptions."""
+        mandatory = self.service.get_mandatory_item_ids(FrontendType.MERCHANT)
+        assert "dashboard" in mandatory
+        assert "subscriptions" in mandatory
+
+    def test_merchant_sections_have_expected_orders(self):
+        """MERCHANT menu sections have the expected order values."""
+        menus = self.service.discover_all_menus()
+        sections = menus[FrontendType.MERCHANT]
+        order_map = {s.id: s.order for s in sections}
+        # main is lowest, account is highest
+        assert order_map["main"] < order_map["billing"]
+        assert order_map["billing"] < order_map["loyalty"]
+        assert order_map["loyalty"] < order_map["account"]
+
+
+@pytest.mark.unit
+@pytest.mark.core
+class TestMenuDiscoveryServiceEnabledModuleCodes:
+    """Test enabled_module_codes parameter on get_menu_sections_for_frontend."""
+
+    def setup_method(self):
+        self.service = MenuDiscoveryService()
+
+    def test_all_modules_enabled_shows_all_sections(self, db):
+        """When all module codes are provided, all sections appear."""
+        enabled = {"core", "billing", "tenancy", "loyalty"}
+        sections = self.service.get_menu_sections_for_frontend(
+            db, FrontendType.MERCHANT, enabled_module_codes=enabled,
+        )
+        section_ids = {s.id for s in sections}
+        assert "main" in section_ids
+        assert "billing" in section_ids
+        assert "account" in section_ids
+        assert "loyalty" in section_ids
+
+    def test_loyalty_disabled_hides_loyalty_section(self, db):
+        """When loyalty is not in enabled_module_codes, its section still appears
+        but items are marked as disabled (filtered out by get_menu_for_frontend)."""
+        enabled = {"core", "billing", "tenancy"}
+        sections = self.service.get_menu_sections_for_frontend(
+            db, FrontendType.MERCHANT, enabled_module_codes=enabled,
+        )
+        # Sections still exist, but loyalty items are marked disabled
+        loyalty_sections = [s for s in sections if s.id == "loyalty"]
+        if loyalty_sections:
+            for item in loyalty_sections[0].items:
+                assert item.is_module_enabled is False
+
+    def test_get_menu_for_frontend_filters_disabled_modules(self, db):
+        """get_menu_for_frontend removes items from disabled modules."""
+        enabled = {"core", "billing", "tenancy"}  # No loyalty
+        sections = self.service.get_menu_for_frontend(
+            db, FrontendType.MERCHANT, enabled_module_codes=enabled,
+        )
+        section_ids = {s.id for s in sections}
+        assert "main" in section_ids
+        assert "billing" in section_ids
+        assert "account" in section_ids
+        assert "loyalty" not in section_ids, "Loyalty section should be filtered out"
+
+    def test_get_menu_for_frontend_includes_loyalty_when_enabled(self, db):
+        """get_menu_for_frontend includes loyalty when its module is enabled."""
+        enabled = {"core", "billing", "tenancy", "loyalty"}
+        sections = self.service.get_menu_for_frontend(
+            db, FrontendType.MERCHANT, enabled_module_codes=enabled,
+        )
+        section_ids = {s.id for s in sections}
+        assert "loyalty" in section_ids
+
+    def test_core_only_shows_minimal_sections(self, db):
+        """With only core modules, only main section appears."""
+        enabled = {"core"}
+        sections = self.service.get_menu_for_frontend(
+            db, FrontendType.MERCHANT, enabled_module_codes=enabled,
+        )
+        section_ids = {s.id for s in sections}
+        assert "main" in section_ids
+        assert "billing" not in section_ids
+        assert "loyalty" not in section_ids
+
+    def test_enabled_module_codes_none_shows_all(self, db):
+        """When enabled_module_codes is None and no platform_id, all modules shown."""
+        sections = self.service.get_menu_for_frontend(
+            db, FrontendType.MERCHANT, enabled_module_codes=None,
+        )
+        section_ids = {s.id for s in sections}
+        assert "main" in section_ids
+        assert "billing" in section_ids
+        assert "loyalty" in section_ids
+        assert "account" in section_ids

app/modules/core/tests/unit/test_menu_service.py

@@ -3,6 +3,7 @@
 import pytest
 
 from app.modules.core.services.menu_service import MenuService
+from app.modules.enums import FrontendType
 
 
 @pytest.mark.unit
@@ -16,3 +17,96 @@ class TestMenuService:
     def test_service_instantiation(self):
         """Service can be instantiated."""
         assert self.service is not None
+
+
+@pytest.mark.unit
+@pytest.mark.core
+class TestMenuServiceMerchantRendering:
+    """Test get_menu_for_rendering with FrontendType.MERCHANT and enabled_module_codes."""
+
+    def setup_method(self):
+        self.service = MenuService()
+
+    def test_render_merchant_menu_all_modules(self, db):
+        """Rendering with all modules shows all sections."""
+        enabled = {"core", "billing", "tenancy", "loyalty"}
+        sections = self.service.get_menu_for_rendering(
+            db=db,
+            frontend_type=FrontendType.MERCHANT,
+            enabled_module_codes=enabled,
+        )
+        section_ids = {s.id for s in sections}
+        assert "main" in section_ids
+        assert "billing" in section_ids
+        assert "account" in section_ids
+        assert "loyalty" in section_ids
+
+    def test_render_merchant_menu_without_loyalty(self, db):
+        """Rendering without loyalty module hides loyalty section."""
+        enabled = {"core", "billing", "tenancy"}
+        sections = self.service.get_menu_for_rendering(
+            db=db,
+            frontend_type=FrontendType.MERCHANT,
+            enabled_module_codes=enabled,
+        )
+        section_ids = {s.id for s in sections}
+        assert "loyalty" not in section_ids
+        assert "main" in section_ids
+        assert "billing" in section_ids
+
+    def test_render_merchant_menu_section_item_structure(self, db):
+        """Each section has items with expected attributes."""
+        enabled = {"core", "billing", "tenancy", "loyalty"}
+        sections = self.service.get_menu_for_rendering(
+            db=db,
+            frontend_type=FrontendType.MERCHANT,
+            enabled_module_codes=enabled,
+        )
+        for section in sections:
+            assert section.id
+            assert len(section.items) > 0
+            for item in section.items:
+                assert item.id
+                assert item.label_key
+                assert item.icon
+                assert item.route
+                assert item.route.startswith("/merchants/")
+
+    def test_render_merchant_menu_section_ordering(self, db):
+        """Sections are returned in correct order."""
+        enabled = {"core", "billing", "tenancy", "loyalty"}
+        sections = self.service.get_menu_for_rendering(
+            db=db,
+            frontend_type=FrontendType.MERCHANT,
+            enabled_module_codes=enabled,
+        )
+        orders = [s.order for s in sections]
+        assert orders == sorted(orders)
+
+    def test_render_merchant_menu_no_enabled_modules_returns_nothing(self, db):
+        """With empty enabled set, no sections are returned."""
+        sections = self.service.get_menu_for_rendering(
+            db=db,
+            frontend_type=FrontendType.MERCHANT,
+            enabled_module_codes=set(),
+        )
+        assert len(sections) == 0
+
+    def test_enabled_module_codes_propagated(self, db):
+        """enabled_module_codes parameter is properly propagated to discovery service."""
+        # With loyalty
+        with_loyalty = self.service.get_menu_for_rendering(
+            db=db,
+            frontend_type=FrontendType.MERCHANT,
+            enabled_module_codes={"core", "billing", "tenancy", "loyalty"},
+        )
+        # Without loyalty
+        without_loyalty = self.service.get_menu_for_rendering(
+            db=db,
+            frontend_type=FrontendType.MERCHANT,
+            enabled_module_codes={"core", "billing", "tenancy"},
+        )
+        with_ids = {s.id for s in with_loyalty}
+        without_ids = {s.id for s in without_loyalty}
+        assert "loyalty" in with_ids
+        assert "loyalty" not in without_ids