chore: fix eslint errors introduced across phases 1-3

apps/agent-worker/src/terminal-token.ts

@@ -37,7 +37,8 @@ export const parseBoxTokenUsername = (token: string): string | null => {
   const parts = token.split('.');
   if (parts.length !== 4 || parts[1] !== 'box') return null;
   const username = parts[2];
-  return username ? username : null;
+  if (!username) return null;
+  return username;
 };
 
 // User-scoped variant authorizing a terminal connection to a user's box.