refactor: identify and freeze messages at creation

packages/context/session-reference/src/index.ts

@@ -8,8 +8,9 @@
 import { Context, Service } from 'cordis'
 import z from 'schemastery'
 import type { Agent } from '@deepseek-ai/dsh-agent'
+import { createUserMessage } from '@deepseek-ai/dsh-llm'
 import type { ContentBlock } from '@deepseek-ai/dsh-llm'
-import type { SessionId, UserMessageData } from '@deepseek-ai/dsh-session'
+import type { SessionId, UserMessage } from '@deepseek-ai/dsh-session'
 import type { SessionSurfaceSnapshot } from '@deepseek-ai/dsh-session-query'
 import {
   DEFAULT_CANDIDATE_LIMIT,
@@ -192,10 +193,10 @@ export class SessionReferenceService extends Service {
         inputIndex: index,
       })),
     }
-    const additionalContext: UserMessageData = {
+    const additionalContext: UserMessage = createUserMessage({
       source,
       content: [{ type: 'text', text: prompt }],
-    }
+    })
     return { content: acceptedContent, additionalContext }
   }