refactor(context): require directory service dependencies

tests/test_route_context_contract.py

@@ -1,6 +1,7 @@
 import pytest
 
 from core.routes.context import RouteContext
+from core.services.directory_service import DirectoryService
 from core.services.scanner_service import ScannerService
 
 
@@ -17,3 +18,11 @@ def test_route_context_remains_immutable_after_construction():
 def test_scanner_service_requires_mandatory_route_dependencies():
     with pytest.raises(KeyError, match="Missing route dependency: asyncio"):
         ScannerService(RouteContext({}))
+
+
+def test_directory_service_requires_mandatory_route_dependencies():
+    with pytest.raises(
+        KeyError,
+        match="Missing route dependency: TEMPLATE_KEY_ALIASES",
+    ):
+        DirectoryService(RouteContext({}))