feat: 实现 ACP session/delete + message-id 两个 UNSTABLE RFD

session/delete（rfds/session-delete.mdx）：
- sessionCapabilities.delete: {} 能力广告（类型增强写入,SDK 0.19.0 早于该 RFD）
- extMethod 钩子路由 session/delete → unstable_deleteSession
- 硬删除 .jsonl 文件,ENOENT 视为成功（幂等）
- 未知方法抛 RequestError.methodNotFound（JSON-RPC -32601）

message-id（rfds/message-id.mdx）：
- agent_message_chunk / user_message_chunk / agent_thought_chunk 携带 messageId
- forwardSessionUpdates 维护 currentAgentMessageId,lazy 生成 UUID
- streaming text/thinking chunks 与最终 assistant message 共享同一 ID
- replayHistoryMessages per-message 生成 UUID
- PromptRequest.messageId → PromptResponse.userMessageId 回显
- tool_call / plan / subagent 不带 messageId（spec 仅规定 chunk 类型）

测试：ACP service 从 176 → 191 (+15)
- bridge.test.ts: +9 个 message-id 测试
- agent.test.ts: +6 个 session/delete + userMessageId 测试
- 总测试 5851 → 5866,全通过

审计文档：新增附录 A.2 记录两个 UNSTABLE RFD 实现状态

Co-Authored-By: glm-5.2 <zai-org@claude-code-best.win>

src/services/acp/bridge/notifications.ts

@@ -40,6 +40,10 @@ export function toAcpNotifications(
     parentToolUseId?: string | null
     cwd?: string
     streamingActive?: boolean
+    // Per message-id.mdx RFD: UUID identifying the message these chunks
+    // belong to. Only attached to agent_message_chunk / user_message_chunk /
+    // agent_thought_chunk (spec scope). undefined = omit the field entirely.
+    messageId?: string
   },
 ): SessionNotification[] {
   const output: SessionNotification[] = []
@@ -55,6 +59,7 @@ export function toAcpNotifications(
         update = {
           sessionUpdate:
             role === 'assistant' ? 'agent_message_chunk' : 'user_message_chunk',
+          ...(options?.messageId ? { messageId: options.messageId } : {}),
           content: { type: 'text', text },
         }
         break
@@ -65,6 +70,7 @@ export function toAcpNotifications(
         const thinking = (chunk.thinking as string) ?? ''
         update = {
           sessionUpdate: 'agent_thought_chunk',
+          ...(options?.messageId ? { messageId: options.messageId } : {}),
           content: { type: 'text', text: thinking },
         }
         break
@@ -78,6 +84,7 @@ export function toAcpNotifications(
               role === 'assistant'
                 ? 'agent_message_chunk'
                 : 'user_message_chunk',
+            ...(options?.messageId ? { messageId: options.messageId } : {}),
             content: {
               type: 'image',
               data: source.data as string,
@@ -237,6 +244,7 @@ export function assistantMessageToAcpNotifications(
     parentToolUseId?: string | null
     cwd?: string
     streamingActive?: boolean
+    messageId?: string
   },
 ): SessionNotification[] {
   const message = msg.message as Record<string, unknown> | undefined
@@ -255,6 +263,7 @@ export function assistantMessageToAcpNotifications(
         sessionId,
         update: {
           sessionUpdate: 'agent_message_chunk',
+          ...(options?.messageId ? { messageId: options.messageId } : {}),
           content: { type: 'text', text: content },
         },
       },
@@ -296,6 +305,7 @@ export function streamEventToAcpNotifications(
     clientCapabilities?: ClientCapabilities
     cwd?: string
     streamingActive?: boolean
+    messageId?: string
   },
 ): SessionNotification[] {
   const event = (msg as unknown as { event: Record<string, unknown> }).event
@@ -318,6 +328,7 @@ export function streamEventToAcpNotifications(
           clientCapabilities: options?.clientCapabilities,
           parentToolUseId: msg.parent_tool_use_id as string | null | undefined,
           cwd: options?.cwd,
+          messageId: options?.messageId,
         },
       )
     }
@@ -335,6 +346,7 @@ export function streamEventToAcpNotifications(
           clientCapabilities: options?.clientCapabilities,
           parentToolUseId: msg.parent_tool_use_id as string | null | undefined,
           cwd: options?.cwd,
+          messageId: options?.messageId,
         },
       )
     }