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/createServerLogic.go

@@ -83,6 +83,8 @@ func (l *CreateServerLogic) CreateServer(req *types.CreateServerRequest) error {
 				}
 			}
 		}
+		// Simnet: apply defaults / normalize (no-op for other protocols)
+		protocol.NormalizeSimnet()
 		protocols = append(protocols, protocol)
 	}
 

internal/logic/admin/server/filterServerListLogic.go

@@ -54,6 +54,10 @@ func (l *FilterServerListLogic) FilterServerList(req *types.FilterServerListRequ
 			l.Errorf("[FilterServerList] UnmarshalProtocols Error: %s", err.Error())
 			continue
 		}
+		// Normalize simnet defaults on the response (safe: dst is a fresh slice).
+		for i := range dst {
+			dst[i].NormalizeSimnet()
+		}
 		tool.DeepCopy(&protocols, dst)
 		server.Protocols = protocols
 

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{

internal/logic/admin/server/updateServerLogic.go

@@ -100,6 +100,8 @@ func (l *UpdateServerLogic) UpdateServer(req *types.UpdateServerRequest) error {
 				}
 			}
 		}
+		// Simnet: apply defaults / normalize (no-op for other protocols)
+		protocol.NormalizeSimnet()
 		protocols = append(protocols, protocol)
 	}
 	err = data.MarshalProtocols(protocols)