feat: status_reason field for workflows + proper failure logging

- Add status_reason column to workflows table (migration)
- AgentUpdate::WorkflowStatus and WorkflowComplete carry reason
- Dispatch failure logs to execution_log with reason
- Worker disconnect marks orphaned workflows as failed with reason
- All status transitions now have traceable cause

src/agent.rs

@@ -158,15 +158,20 @@ impl AgentManager {
                         tracing::info!("Workflow {} dispatched to worker '{}'", workflow_id, name);
                     }
                     Err(e) => {
-                        tracing::error!("Failed to dispatch workflow {}: {}", workflow_id, e);
+                        let reason = format!("调度失败: {}", e);
-                        let _ = sqlx::query("UPDATE workflows SET status = 'failed' WHERE id = ?")
+                        tracing::error!("Failed to dispatch workflow {}: {}", workflow_id, reason);
-                            .bind(&workflow_id).execute(&self.pool).await;
+                        let _ = sqlx::query("UPDATE workflows SET status = 'failed', status_reason = ? WHERE id = ?")
-                        let _ = btx.send(WsMessage::WorkflowStatusUpdate {
+                            .bind(&reason).bind(&workflow_id).execute(&self.pool).await;
-                            workflow_id,
+                        // Log to execution_log so frontend can show the reason
-                            status: "failed".into(),
+                        let log_id = uuid::Uuid::new_v4().to_string();
+                        let _ = sqlx::query(
+                            "INSERT INTO execution_log (id, workflow_id, step_order, tool_name, tool_input, output, status, created_at) VALUES (?, ?, 0, 'system', 'dispatch', ?, 'failed', datetime('now'))"
+                        ).bind(&log_id).bind(&workflow_id).bind(&reason).execute(&self.pool).await;
+                        let _ = btx.send(WsMessage::StepStatusUpdate {
+                            step_id: log_id, status: "failed".into(), output: reason,
                         });
-                        let _ = btx.send(WsMessage::Error {
+                        let _ = btx.send(WsMessage::WorkflowStatusUpdate {
-                            message: format!("No worker available: {}", e),
+                            workflow_id, status: "failed".into(),
                         });
                     }
                 }
@@ -745,6 +750,7 @@ pub async fn run_step_loop(
                         let _ = update_tx.send(AgentUpdate::WorkflowStatus {
                             workflow_id: workflow_id.to_string(),
                             status: "waiting_user".into(),
+                            reason: String::new(),
                         }).await;
                         send_execution(update_tx, workflow_id, step_order, "ask_user", reason, reason, "waiting").await;
 
@@ -789,6 +795,7 @@ pub async fn run_step_loop(
                         let _ = update_tx.send(AgentUpdate::WorkflowStatus {
                             workflow_id: workflow_id.to_string(),
                             status: "executing".into(),
+                            reason: String::new(),
                         }).await;
 
                         let tool_msg = if feedback.is_empty() {
@@ -1084,6 +1091,7 @@ pub async fn run_agent_loop(
                             let _ = update_tx.send(AgentUpdate::WorkflowStatus {
                                 workflow_id: workflow_id.to_string(),
                                 status: "waiting_user".into(),
+                                reason: String::new(),
                             }).await;
                             send_execution(update_tx, workflow_id, 0, "plan_approval", "等待确认计划", "等待用户确认执行计划", "waiting").await;
 
@@ -1114,6 +1122,7 @@ pub async fn run_agent_loop(
                                 let _ = update_tx.send(AgentUpdate::WorkflowStatus {
                                     workflow_id: workflow_id.to_string(),
                                     status: "executing".into(),
+                                    reason: String::new(),
                                 }).await;
                                 // Stay in Planning phase, continue the loop
                                 continue;
@@ -1130,6 +1139,7 @@ pub async fn run_agent_loop(
                             let _ = update_tx.send(AgentUpdate::WorkflowStatus {
                                 workflow_id: workflow_id.to_string(),
                                 status: "executing".into(),
+                                reason: String::new(),
                             }).await;
                         }
 

src/db.rs

@@ -322,6 +322,16 @@ impl Database {
             }
         }
 
+        // Migration: add status_reason to workflows
+        let has_status_reason: bool = sqlx::query_scalar::<_, i32>(
+            "SELECT COUNT(*) FROM pragma_table_info('workflows') WHERE name='status_reason'"
+        ).fetch_one(&self.pool).await.unwrap_or(0) > 0;
+        if !has_status_reason {
+            let _ = sqlx::query(
+                "ALTER TABLE workflows ADD COLUMN status_reason TEXT NOT NULL DEFAULT ''"
+            ).execute(&self.pool).await;
+        }
+
         Ok(())
     }
 }
@@ -348,6 +358,8 @@ pub struct Workflow {
     pub created_at: String,
     pub report: String,
     pub template_id: String,
+    #[serde(default)]
+    pub status_reason: String,
 }
 
 #[derive(Debug, Clone, Serialize, Deserialize, sqlx::FromRow)]

src/sink.rs

@@ -14,12 +14,12 @@ use crate::state::{AgentState, Artifact};
 #[serde(tag = "kind")]
 pub enum AgentUpdate {
     PlanUpdate { workflow_id: String, steps: Vec<PlanStepInfo> },
-    WorkflowStatus { workflow_id: String, status: String },
+    WorkflowStatus { workflow_id: String, status: String, #[serde(default)] reason: String },
     Activity { workflow_id: String, activity: String },
     ExecutionLog { workflow_id: String, step_order: i32, tool_name: String, tool_input: String, output: String, status: String },
     LlmCallLog { workflow_id: String, step_order: i32, phase: String, messages_count: i32, tools_count: i32, tool_calls: String, text_response: String, prompt_tokens: Option<u32>, completion_tokens: Option<u32>, latency_ms: i64 },
     StateSnapshot { workflow_id: String, step_order: i32, state: AgentState },
-    WorkflowComplete { workflow_id: String, status: String },
+    WorkflowComplete { workflow_id: String, status: String, #[serde(default)] reason: String },
     ArtifactSave { workflow_id: String, step_order: i32, artifact: Artifact },
     RequirementUpdate { workflow_id: String, requirement: String },
     /// base64-encoded file content
@@ -61,9 +61,9 @@ pub async fn handle_single_update(
         AgentUpdate::PlanUpdate { workflow_id, steps } => {
             bcast(broadcast_tx, WsMessage::PlanUpdate { workflow_id: workflow_id.clone(), steps: steps.clone() });
         }
-        AgentUpdate::WorkflowStatus { workflow_id, status } => {
+        AgentUpdate::WorkflowStatus { workflow_id, status, reason } => {
-            let _ = sqlx::query("UPDATE workflows SET status = ? WHERE id = ?")
+            let _ = sqlx::query("UPDATE workflows SET status = ?, status_reason = ? WHERE id = ?")
-                .bind(status).bind(workflow_id).execute(pool).await;
+                .bind(status).bind(reason).bind(workflow_id).execute(pool).await;
             bcast(broadcast_tx, WsMessage::WorkflowStatusUpdate { workflow_id: workflow_id.clone(), status: status.clone() });
         }
         AgentUpdate::Activity { workflow_id, activity } => {
@@ -100,9 +100,9 @@ pub async fn handle_single_update(
                 "INSERT INTO agent_state_snapshots (id, workflow_id, step_order, state_json, created_at) VALUES (?, ?, ?, ?, datetime('now'))"
             ).bind(&id).bind(workflow_id).bind(step_order).bind(&json).execute(pool).await;
         }
-        AgentUpdate::WorkflowComplete { workflow_id, status } => {
+        AgentUpdate::WorkflowComplete { workflow_id, status, reason } => {
-            let _ = sqlx::query("UPDATE workflows SET status = ? WHERE id = ?")
+            let _ = sqlx::query("UPDATE workflows SET status = ?, status_reason = ? WHERE id = ?")
-                .bind(status).bind(workflow_id).execute(pool).await;
+                .bind(status).bind(reason).bind(workflow_id).execute(pool).await;
             bcast(broadcast_tx, WsMessage::WorkflowStatusUpdate { workflow_id: workflow_id.clone(), status: status.clone() });
         }
         AgentUpdate::ArtifactSave { workflow_id, step_order, artifact } => {

src/worker.rs

@@ -163,4 +163,13 @@ impl WorkerManager {
     pub async fn complete_workflow(&self, workflow_id: &str) {
         self.assignments.write().await.remove(workflow_id);
     }
+
+    /// List all workflows assigned to a worker.
+    pub async fn assignments_for_worker(&self, worker_name: &str) -> Vec<String> {
+        self.assignments.read().await
+            .iter()
+            .filter(|(_, w)| w.as_str() == worker_name)
+            .map(|(wf_id, _)| wf_id.clone())
+            .collect()
+    }
 }

src/worker_runner.rs

@@ -194,9 +194,11 @@ async fn connect_and_run(server_url: &str, worker_name: &str, llm_config: &crate
                 // Sync all workspace files to server
                 sync_workspace(&update_tx, &project_id, &workdir).await;
 
+                let reason = if let Err(ref e) = result { format!("{}", e) } else { String::new() };
                 let _ = update_tx.send(AgentUpdate::WorkflowComplete {
                     workflow_id: workflow_id.clone(),
                     status: final_status.into(),
+                    reason,
                 }).await;
 
                 *comment_tx.lock().await = None;

src/ws_worker.rs

@@ -111,6 +111,23 @@ async fn handle_worker_socket(socket: WebSocket, state: Arc<WsWorkerState>) {
         _ = recv_task => {},
     }
 
+    // Log reason for any orphaned workflows before cleanup
+    let orphan_workflows: Vec<String> = {
+        let assignments = mgr_for_cleanup.assignments_for_worker(&name_clone).await;
+        assignments
+    };
+    if !orphan_workflows.is_empty() {
+        let reason = format!("Worker '{}' 断开连接", name_clone);
+        for wf_id in &orphan_workflows {
+            let _ = sqlx::query("UPDATE workflows SET status = 'failed', status_reason = ? WHERE id = ? AND status IN ('executing', 'planning')")
+                .bind(&reason).bind(wf_id).execute(&state.pool).await;
+            let log_id = uuid::Uuid::new_v4().to_string();
+            let _ = sqlx::query(
+                "INSERT INTO execution_log (id, workflow_id, step_order, tool_name, tool_input, output, status, created_at) VALUES (?, ?, 0, 'system', 'worker_disconnect', ?, 'failed', datetime('now'))"
+            ).bind(&log_id).bind(wf_id).bind(&reason).execute(&state.pool).await;
+            tracing::warn!("Workflow {} orphaned: {}", wf_id, reason);
+        }
+    }
     mgr_for_cleanup.unregister(&name_clone).await;
 }