refactor: identify and freeze messages at creation

packages/ui/jsonrpc/src/server.ts

@@ -8,6 +8,7 @@
 import type { Context } from 'cordis'
 import { resolve } from 'node:path'
 import type { Agent, AgentHandle } from '@deepseek-ai/dsh-agent'
+import { createUserMessage } from '@deepseek-ai/dsh-llm'
 import { carrierKeyOf, type Scoped } from '@deepseek-ai/dsh-scope'
 import { findLastMessageTurnEnd, SessionId, type TurnEndReason } from '@deepseek-ai/dsh-session'
 import type SubagentService from '@deepseek-ai/dsh-subagent'
@@ -140,7 +141,7 @@ export class HarnessSdkServer {
     rec.activePrompt = true
     try {
       rec.lastTurnEnd = undefined
-      rec.handle.agent.followup({ content: params.contentBlocks, source: { kind: 'user' } })
+      rec.handle.agent.followup(createUserMessage({ content: params.contentBlocks, source: { kind: 'user' } }))
       await rec.handle.agent.whenIdle()
       const payload: SessionFinishedNotification = {
         sessionId: params.sessionId,