refactor: identify and freeze messages at creation

docs/cookbook/extension-cookbook.i18n.yaml

@@ -2,5 +2,5 @@
 # side as of the last confirmed-consistent state. Both languages carry equal authority;
 # after editing either side, bring the other along and re-record with:
 #   pnpm run verify-translation-pairing --write docs/cookbook/extension-cookbook.md
-extension-cookbook.md: 51a87be037ddbf6d031d3607da7b70470087334c
-extension-cookbook.zh.md: 389ac87be0a1cd14a7646374909d79e6e00d8b56
+extension-cookbook.md: 36ab56dcdce1166ef69cec7834f6c17be72d89c3
+extension-cookbook.zh.md: 8c8f9486ec592fcc80f1053f54adce2e33798d4b

docs/cookbook/extension-cookbook.md

@@ -40,6 +40,7 @@ A UI plugin renders from the `session/event` feed (the assistant token stream as
 
 ```ts
 import type { Context } from 'cordis'
+import { createUserMessage } from '@deepseek-ai/dsh-llm'
 import { SessionId } from '@deepseek-ai/dsh-session'
 
 declare function render(text: string): void
@@ -54,10 +55,10 @@ export function apply(ctx: Context) {
       render(event.data.chunk.text)
     }
   })
-  onUserInput(text => ctx.agents.get(SessionId('client-session'))?.followup({
+  onUserInput(text => ctx.agents.get(SessionId('client-session'))?.followup(createUserMessage({
     content: [{ type: 'text', text }],
     source: { kind: 'user' },
-  }))
+  })))
 }
 ```
 

docs/cookbook/extension-cookbook.zh.md

@@ -40,6 +40,7 @@ UI 插件从 `session/event` 事件流渲染（助手 token 流以 `assistant/ch
 
 ```ts
 import type { Context } from 'cordis'
+import { createUserMessage } from '@deepseek-ai/dsh-llm'
 import { SessionId } from '@deepseek-ai/dsh-session'
 
 declare function render(text: string): void
@@ -54,10 +55,10 @@ export function apply(ctx: Context) {
       render(event.data.chunk.text)
     }
   })
-  onUserInput(text => ctx.agents.get(SessionId('client-session'))?.followup({
+  onUserInput(text => ctx.agents.get(SessionId('client-session'))?.followup(createUserMessage({
     content: [{ type: 'text', text }],
     source: { kind: 'user' },
-  }))
+  })))
 }
 ```