feat: wire real AgentOS execution

packages/env/src/agent.ts

@@ -16,6 +16,7 @@ const agentEnvSchema = z.object({
   OPENROUTER_API_KEY: z.string().min(1).optional(),
   RIVET_ENDPOINT: z.url(),
   RIVET_PUBLIC_ENDPOINT: z.url().optional(),
+  RIVET_WORKSPACE_TOKEN: z.string().min(32),
 });
 
 export type AgentEnv = z.infer<typeof agentEnvSchema>;