begin jules support, derive inputs

agents/index.ts

@@ -1,9 +1,11 @@
 import { claude } from "./claude.ts";
 import { codex } from "./codex.ts";
+import { jules } from "./jules.ts";
 
 export const agents = {
   claude,
   codex,
+  jules,
 } as const;
 
 export type AgentInputKey = (typeof agents)[keyof typeof agents]["inputKey"];