Fix Client Groups circular imports and module dependencies

app/modules/clients/__init__.py

@@ -1,4 +1,29 @@
-from .api import router as api_router
-from .ui import router as ui_router
+"""Clients module.
+
+Routers are exposed lazily so importing ``app.modules.clients.models`` does
+not initialise the clients API, UI, importer, and related modules. This keeps
+the existing ``api_router`` and ``ui_router`` public exports while preventing
+circular imports with client groups.
+"""
+
+from __future__ import annotations
+
+from typing import Any
 
 __all__ = ["api_router", "ui_router"]
+
+
+def __getattr__(name: str) -> Any:
+    if name == "api_router":
+        from .api import router
+
+        return router
+
+    if name == "ui_router":
+        from .ui import router
+
+        return router
+
+    raise AttributeError(
+        f"module {__name__!r} has no attribute {name!r}"
+    )