feat: implement Redis session management and user authentication flow

app/gateway-api/src/trpc.ts

@@ -0,0 +1,8 @@
+import { initTRPC } from '@trpc/server';
+
+import type { GatewayApiContext } from './context.js';
+
+const t = initTRPC.context<GatewayApiContext>().create();
+
+export const router = t.router;
+export const procedure = t.procedure;