Unknown registrations return 200 instead of 400 error response

[0w3n-d]

When attempting to register an unknown entity, the system currently responds with a 200 status code, which is misleading. The node operator may think the registration was successful, but it actually was not.

Expected behavior:

• The API should return a 400 error response when an unknown registration is attempted.

Actual behavior:

• The API returns a 200 status code even when the registration is unknown and fails.

Impact:

• This may cause node operators to believe a registration went through successfully when it did not, potentially leading to operational confusion and misconfiguration.

Steps to reproduce:

1. Attempt to register an unknown entity
2. Observe that the API returns a 200 response

Proposed solution:

• Return a 400 error code for unknown registration attempts to accurately reflect the error state.