refactor(agent): remove message metadata channel

packages/client/runtime/src/client/sessions/conversation.ts

@@ -74,7 +74,6 @@ export interface ContextMessageNode {
   seq: number
   content: readonly ContentBlock[]
   source: unknown
-  meta?: unknown
 }
 
 /** A tool result paired (when in-window) with its call head. */

packages/client/runtime/src/client/sessions/fold-adapter.ts

@@ -43,7 +43,6 @@ function materializeNode(
       if (event.data.source.kind !== 'user') {
         return {
           kind: 'context', seq: event.seq, content: event.data.content, source: event.data.source,
-          meta: event.data.meta,
         }
       }
       return { kind: 'user', seq: event.seq, content: event.data.content, source: event.data.source }

packages/client/ui-conversation/src/client/chat/MessageItem.tsx

@@ -43,7 +43,7 @@ export const MessageItem = memo(function MessageItem({ node }: MessageItemProps)
     case 'context':
       return (
         <div className={css.contextRow}>
-          <JsonBlock label="上下文注入" payload={{ content: node.content, meta: node.meta }} />
+          <JsonBlock label="上下文注入" payload={{ content: node.content, source: node.source }} />
         </div>
       )
     default:

packages/client/ui-conversation/tests/chat-branch-tails.spec.tsx

@@ -33,7 +33,7 @@ describe('MessageItem arms', () => {
 
   it('context and unknown nodes render their JSON rows', () => {
     const ctxView = render(
-      <MessageItem node={{ kind: 'context', seq: 3, content: [], source: null, meta: { k: 1 } } as never} />,
+      <MessageItem node={{ kind: 'context', seq: 3, content: [], source: null } as never} />,
     )
     expect(ctxView.getByText(/上下文注入/)).toBeTruthy()
     const unknownView = render(