fix(audit): Batch 0-1 文档校准 + let _ = 静默错误修复

Batch 0:
- TRUTH.md 中间件层 14→15 (补 EvolutionMiddleware@78)
- wiki/middleware.md 同步 15 层 + 优先级分类更新
- Store 数字确认 25 个

Batch 1:
- approvals.rs: 3 处 map_err+let _ = 简化为 if let Err
- director.rs: oneshot send 失败添加 debug 日志
- task.rs: 4 处子任务状态更新添加 debug 日志
- chat.rs: 流消息发送和事件 emit 添加 warn/debug 日志
- heartbeat.rs: 告警广播添加 debug 日志 + break 优化

全量测试通过: 719 passed, 0 failed

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

@@ -291,15 +291,19 @@ pub async fn agent_chat_stream(
         );
 
         let (tx, rx) = tokio::sync::mpsc::channel(32);
-        let _ = tx.send(zclaw_runtime::LoopEvent::Delta(confirm_msg)).await;
-        let _ = tx.send(zclaw_runtime::LoopEvent::Complete(
+        if tx.send(zclaw_runtime::LoopEvent::Delta(confirm_msg)).await.is_err() {
+            tracing::warn!("[agent_chat_stream] Failed to send confirm msg to new channel");
+        }
+        if tx.send(zclaw_runtime::LoopEvent::Complete(
             zclaw_runtime::AgentLoopResult {
                 response: String::new(),
                 input_tokens: 0,
                 output_tokens: 0,
                 iterations: 1,
             }
-        )).await;
+        )).await.is_err() {
+            tracing::warn!("[agent_chat_stream] Failed to send complete to new channel");
+        }
         drop(tx);
         (rx, None)
     } else {
@@ -400,10 +404,12 @@ pub async fn agent_chat_stream(
             // Check cancellation flag before each recv
             if cancel_clone.load(std::sync::atomic::Ordering::SeqCst) {
                 tracing::info!("[agent_chat_stream] Stream cancelled for session: {}", session_id);
-                let _ = app.emit("stream:chunk", serde_json::json!({
+                if let Err(e) = app.emit("stream:chunk", serde_json::json!({
                     "sessionId": session_id,
                     "event": StreamChatEvent::Error { message: "已取消".to_string() }
-                }));
+                })) {
+                    tracing::debug!("[agent_chat_stream] Failed to emit cancel event: {}", e);
+                }
                 break;
             }
 
@@ -491,12 +497,14 @@ pub async fn agent_chat_stream(
                 }
                 Err(_) => {
                     tracing::warn!("[agent_chat_stream] Stream idle timeout for session: {}", session_id);
-                    let _ = app.emit("stream:chunk", serde_json::json!({
+                    if let Err(e) = app.emit("stream:chunk", serde_json::json!({
                         "sessionId": session_id,
                         "event": StreamChatEvent::Error {
                             message: "流式响应超时，请重试".to_string()
                         }
-                    }));
+                    })) {
+                        tracing::debug!("[agent_chat_stream] Failed to emit timeout event: {}", e);
+                    }
                     break;
                 }
             }