feat(simnet): add SimNet protocol end-to-end support

- model: SimNet protocol fields + NormalizeSimnet; type+port protocol uniqueness
- server config: OmnXT runtime config delivery via compatible() simnet case
- credentials: derive per-user psk/key_id from subscription (pkg/simnet), no new table
- subscription: adapter buildOmnxtSimnetConfigs + base64 buildOmnxtProtocolLinks + OmnXT SimNet application (migration 02161)
- UA gating: hide experimental protocols from non first-party clients (download + JSON node-list)
- admin: normalize simnet on create/update and on GET responses
- tests: 21 simnet unit tests; full suite green

internal/logic/admin/server/getServerProtocolsLogic.go

@@ -41,6 +41,12 @@ func (l *GetServerProtocolsLogic) GetServerProtocols(req *types.GetServerProtoco
 		l.Errorf("[FilterServerList] UnmarshalProtocols Error: %s", err.Error())
 		return nil, errors.Wrapf(xerr.NewErrCode(xerr.DatabaseQueryError), "[FilterServerList] UnmarshalProtocols Error: %s", err.Error())
 	}
+	// Normalize simnet defaults on the response so the admin UI always sees a
+	// consistent config even for legacy/hand-inserted rows. dst is a fresh slice
+	// (not shared with the DB), so mutating it here is safe.
+	for i := range dst {
+		dst[i].NormalizeSimnet()
+	}
 	tool.DeepCopy(&protocols, dst)
 
 	return &types.GetServerProtocolsResponse{