refactor: remove main session key references and enhance agent-gateway associations

frontend/src/api/generated/model/agentRead.ts

@@ -20,6 +20,7 @@ export interface AgentRead {
   identity_template?: string | null;
   soul_template?: string | null;
   id: string;
+  gateway_id: string;
   is_board_lead?: boolean;
   is_gateway_main?: boolean;
   openclaw_session_id?: string | null;

frontend/src/api/generated/model/gatewayRead.ts

@@ -15,7 +15,6 @@ export interface GatewayRead {
   id: string;
   organization_id: string;
   token?: string | null;
-  main_session_key: string;
   created_at: string;
   updated_at: string;
 }

frontend/src/api/generated/model/gatewaySessionsResponse.ts

@@ -10,6 +10,5 @@
  */
 export interface GatewaySessionsResponse {
   sessions: unknown[];
-  main_session_key?: string | null;
   main_session?: unknown | null;
 }

frontend/src/api/generated/model/gatewaysStatusResponse.ts

@@ -13,7 +13,6 @@ export interface GatewaysStatusResponse {
   gateway_url: string;
   sessions_count?: number | null;
   sessions?: unknown[] | null;
-  main_session_key?: string | null;
   main_session?: unknown | null;
   main_session_error?: string | null;
   error?: string | null;