feat: review feedback, and more changes in cli

backend/src/db/migrations/20250212191958_create-gateway.ts

@@ -52,6 +52,7 @@ export async function up(knex: Knex): Promise<void> {
       t.string("keyAlgorithm").notNullable();
       t.datetime("issuedAt").notNullable();
       t.datetime("expiration").notNullable();
+      t.datetime("heartbeat");
 
       t.binary("relayAddress").notNullable();
 

backend/src/db/schemas/gateways.ts

@@ -16,6 +16,7 @@ export const GatewaysSchema = z.object({
   keyAlgorithm: z.string(),
   issuedAt: z.date(),
   expiration: z.date(),
+  heartbeat: z.date().nullable().optional(),
   relayAddress: zodBuffer,
   orgGatewayRootCaId: z.string().uuid(),
   identityId: z.string().uuid(),