refactor: remove legacy /shop and /api/v1/shop dead code

After the storefront migration, no live routes mount under /api/v1/shop/.
Remove all dead code that detected/handled shop API requests: the
is_shop_api_request() method, the shop API dispatch branch in middleware,
the RequestContext.SHOP enum member (renamed to STOREFRONT), legacy path
prefixes in FrontendDetector, and all associated tests.

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

tests/integration/middleware/conftest.py

@@ -26,7 +26,7 @@ from main import app
 from tests.integration.middleware.middleware_test_routes import (
     admin_router,
     api_router,
-    shop_router,
+    storefront_router,
     store_router,
 )
 from tests.integration.middleware.middleware_test_routes import (
@@ -39,7 +39,7 @@ if not any(r.path.startswith("/middleware-test") for r in app.routes if hasattr(
     app.include_router(api_router)
     app.include_router(admin_router)
     app.include_router(store_router)
-    app.include_router(shop_router)
+    app.include_router(storefront_router)
 
 
 @pytest.fixture

tests/integration/middleware/middleware_test_routes.py

@@ -10,7 +10,7 @@ IMPORTANT: Routes are organized by prefix to avoid conflicts:
 - /api/middleware-test/* - API context testing
 - /admin/middleware-test/* - Admin context testing
 - /store/middleware-test/* - Store dashboard context testing
-- /shop/middleware-test/* - Shop context testing
+- /storefront/middleware-test/* - Storefront context testing
 """
 
 from fastapi import APIRouter, Request
@@ -531,15 +531,15 @@ async def test_store_dashboard_theme(request: Request):
 
 
 # =============================================================================
-# Shop Context Test Router
+# Storefront Context Test Router
 # =============================================================================
 
-shop_router = APIRouter(prefix="/shop/middleware-test")
+storefront_router = APIRouter(prefix="/storefront/middleware-test")
 
 
-@shop_router.get("/context")
-async def test_shop_context(request: Request):
-    """Test shop context detection."""
+@storefront_router.get("/context")
+async def test_storefront_context(request: Request):
+    """Test storefront context detection."""
     context_type = getattr(request.state, "context_type", None)
     store = getattr(request.state, "store", None)
     theme = getattr(request.state, "theme", None)
@@ -552,9 +552,9 @@ async def test_shop_context(request: Request):
     }
 
 
-@shop_router.get("/custom-domain-context")
-async def test_shop_custom_domain_context(request: Request):
-    """Test shop context with custom domain."""
+@storefront_router.get("/custom-domain-context")
+async def test_storefront_custom_domain_context(request: Request):
+    """Test storefront context with custom domain."""
     context_type = getattr(request.state, "context_type", None)
     store = getattr(request.state, "store", None)
     return {
@@ -564,9 +564,9 @@ async def test_shop_custom_domain_context(request: Request):
     }
 
 
-@shop_router.get("/theme")
-async def test_shop_theme(request: Request):
-    """Test theme in shop context."""
+@storefront_router.get("/theme")
+async def test_storefront_theme(request: Request):
+    """Test theme in storefront context."""
     context_type = getattr(request.state, "context_type", None)
     theme = getattr(request.state, "theme", None)
     colors = theme.get("colors", {}) if theme else {}