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

crates/zclaw-runtime/src/tool/builtin/task.rs

@@ -112,12 +112,14 @@ impl Tool for TaskTool {
         let task_id = sub_agent_id.to_string();
 
         if let Some(ref tx) = context.event_sender {
-            let _ = tx.send(LoopEvent::SubtaskStatus {
+            if tx.send(LoopEvent::SubtaskStatus {
                 task_id: task_id.clone(),
                 description: description.to_string(),
                 status: "started".to_string(),
                 detail: None,
-            }).await;
+            }).await.is_err() {
+                tracing::debug!("[TaskTool] Subtask status dropped: parent loop ended");
+            }
         }
 
         // Create a fresh session for the sub-agent
@@ -161,12 +163,14 @@ impl Tool for TaskTool {
 
         // Emit subtask_running event
         if let Some(ref tx) = context.event_sender {
-            let _ = tx.send(LoopEvent::SubtaskStatus {
+            if tx.send(LoopEvent::SubtaskStatus {
                 task_id: task_id.clone(),
                 description: description.to_string(),
                 status: "running".to_string(),
                 detail: Some("子Agent正在执行中...".to_string()),
-            }).await;
+            }).await.is_err() {
+                tracing::debug!("[TaskTool] Subtask status dropped: parent loop ended");
+            }
         }
 
         // Execute the sub-agent loop (non-streaming — collect full result)
@@ -179,7 +183,7 @@ impl Tool for TaskTool {
 
                 // Emit subtask_completed event
                 if let Some(ref tx) = context.event_sender {
-                    let _ = tx.send(LoopEvent::SubtaskStatus {
+                    if tx.send(LoopEvent::SubtaskStatus {
                         task_id: task_id.clone(),
                         description: description.to_string(),
                         status: "completed".to_string(),
@@ -187,7 +191,9 @@ impl Tool for TaskTool {
                             "完成 ({}次迭代, {}输入token)",
                             loop_result.iterations, loop_result.input_tokens
                         )),
-                    }).await;
+                    }).await.is_err() {
+                        tracing::debug!("[TaskTool] Subtask status dropped: parent loop ended");
+                    }
                 }
 
                 json!({
@@ -204,12 +210,14 @@ impl Tool for TaskTool {
 
                 // Emit subtask_failed event
                 if let Some(ref tx) = context.event_sender {
-                    let _ = tx.send(LoopEvent::SubtaskStatus {
+                    if tx.send(LoopEvent::SubtaskStatus {
                         task_id: task_id.clone(),
                         description: description.to_string(),
                         status: "failed".to_string(),
                         detail: Some(e.to_string()),
-                    }).await;
+                    }).await.is_err() {
+                        tracing::debug!("[TaskTool] Subtask status dropped: parent loop ended");
+                    }
                 }
 
                 json!({