fix(identity): 接通身份信号提取与持久化 — 对话中起名跨会话记忆

根因: 记忆提取管道(COMBINED_EXTRACTION_PROMPT)提取5种画像信号
但无身份信号(agent_name/user_name)，不存在从对话到AgentConfig.name
或IdentityFiles的写回路径。

修复内容:
- ProfileSignals 增加 agent_name/user_name 字段
- COMBINED_EXTRACTION_PROMPT 增加身份提取指令
- parse_profile_signals 解析新字段 + 回退推断
- GrowthIntegration 存储身份信号到 VikingStorage
- post_conversation_hook 写回 soul.md + emit Tauri 事件
- streamStore 规则化检测 agent 名字并更新 AgentConfig.name
- cold-start-mapper 新增 detectAgentNameSuggestion

链路: 对话→提取→VikingStorage→hook写回soul.md→事件→前端刷新

desktop/src-tauri/src/kernel_commands/chat.rs

@@ -324,6 +324,7 @@ pub async fn agent_chat_stream(
 
     let hb_state = heartbeat_state.inner().clone();
     let rf_state = reflection_state.inner().clone();
+    let id_state_hook = identity_state.inner().clone();
 
     // Clone the guard map for cleanup in the spawned task
     let guard_map: SessionStreamGuard = stream_guard.inner().clone();
@@ -380,12 +381,14 @@ pub async fn agent_chat_stream(
                         let hb = hb_state.clone();
                         let rf = rf_state.clone();
                         let driver = llm_driver.clone();
+                        let id_state = id_state_hook.clone();
+                        let app_hook = app.clone();
                         if driver.is_none() {
                             tracing::debug!("[agent_chat_stream] Post-hook firing without LLM driver (schedule intercept path)");
                         }
                         tokio::spawn(async move {
                             crate::intelligence_hooks::post_conversation_hook(
-                                &agent_id_hook, &message_hook, &hb, &rf, driver,
+                                &agent_id_hook, &message_hook, &hb, &rf, driver, &id_state, &app_hook,
                             ).await;
                         });
                     }