fix(security): harden channel token and id generation

src/infra/secure-random.ts

@@ -0,0 +1,9 @@
+import { randomBytes, randomUUID } from "node:crypto";
+
+export function generateSecureUuid(): string {
+  return randomUUID();
+}
+
+export function generateSecureToken(bytes = 16): string {
+  return randomBytes(bytes).toString("base64url");
+}