docs: address final model experience review

packages/core/agent/README.md

@@ -50,7 +50,7 @@ The handle every plugin programs against:
 
 - Agent creation: `AgentLoop.create()` is the concrete config-path implementation (in `dsh-agent-loop`), while programmatic consumers create/resume owned agents through `ctx.agents.create()` / `ctx.agents.resume()`. Replace the loop by implementing `Agent` and registering via `ctx.agents.register()`.
 - Event listeners: all `agent/*` events are declared here — no dependency on the loop package needed.
-- Subagent delegation: implemented by `@deepseek-ai/dsh-subagent`, not by a method on `Agent`; providers create or drive ordinary `Agent` handles through the factory seam, so spawn/fork/ACP transports stay outside the core agent interface.
+- Subagent delegation is not an `Agent` method; providers create or drive ordinary handles through the factory seam, so delegation transports stay outside the core agent interface.
 
 ## Model Experience