Add endpoint for creating local contacts with access control

Introduced a new `local_contact_router` to handle creation of local contacts. The endpoint enforces role-based access control and ensures no duplication of email addresses. Updated the router exports for consistency and cleaned up a large test file to improve readability.

backend/app/routers/protected_router.py

@@ -5,6 +5,7 @@ from app.routers.address import address_router
 from app.routers.contact import contact_router
 from app.routers.shipment import shipment_router
 from app.routers.dewar import dewar_router
+from app.routers.local_contact import local_contact_router
 
 protected_router = APIRouter(
     dependencies=[Depends(get_current_user)]  # Applies to all routes
@@ -12,6 +13,9 @@ protected_router = APIRouter(
 
 protected_router.include_router(address_router, prefix="/addresses", tags=["addresses"])
 protected_router.include_router(contact_router, prefix="/contacts", tags=["contacts"])
+protected_router.include_router(
+    local_contact_router, prefix="/local-contacts", tags=["local-contacts"]
+)
 protected_router.include_router(
     shipment_router, prefix="/shipments", tags=["shipments"]
 )