feat: real-time activity indicator in log panel

- New WsMessage::ActivityUpdate for live status broadcasting
- Shows current activity at bottom of log: LLM calls, tool execution, user approval
- Activity bar with spinner, auto-clears on workflow completion
- Status badge with pulse animation in log header

src/agent.rs

@@ -36,6 +36,7 @@ pub enum WsMessage {
     ReportReady { workflow_id: String },
     ProjectUpdate { project_id: String, name: String },
     LlmCallLog { workflow_id: String, entry: crate::db::LlmCallLogEntry },
+    ActivityUpdate { workflow_id: String, activity: String },
     Error { message: String },
 }
 
@@ -1109,6 +1110,10 @@ async fn run_step_loop(
         let phase_label = format!("step({})", step_order);
 
         tracing::info!("[workflow {}] Step {} LLM call #{} msgs={}", workflow_id, step_order, iteration + 1, messages.len());
+        let _ = broadcast_tx.send(WsMessage::ActivityUpdate {
+            workflow_id: workflow_id.to_string(),
+            activity: format!("步骤 {} — 等待 LLM 响应...", step_order),
+        });
         let call_start = std::time::Instant::now();
         let response = match llm.chat_with_tools(messages, &step_tools).await {
             Ok(r) => r,
@@ -1185,6 +1190,10 @@ async fn run_step_loop(
 
                     "wait_for_approval" => {
                         let reason = args["reason"].as_str().unwrap_or("等待确认");
+                        let _ = broadcast_tx.send(WsMessage::ActivityUpdate {
+                            workflow_id: workflow_id.to_string(),
+                            activity: format!("步骤 {} — 等待用户确认: {}", step_order, reason),
+                        });
 
                         // Broadcast waiting status
                         let _ = broadcast_tx.send(WsMessage::PlanUpdate {
@@ -1350,6 +1359,10 @@ async fn run_step_loop(
 
                     // External tools
                     name if external_tools.as_ref().is_some_and(|e| e.has_tool(name)) => {
+                        let _ = broadcast_tx.send(WsMessage::ActivityUpdate {
+                            workflow_id: workflow_id.to_string(),
+                            activity: format!("步骤 {} — 工具: {}", step_order, name),
+                        });
                         let result = match external_tools.unwrap().invoke(name, &tc.function.arguments, workdir).await {
                             Ok(output) => {
                                 let truncated = truncate_str(&output, 8192);
@@ -1364,6 +1377,20 @@ async fn run_step_loop(
 
                     // IO tools: execute, read_file, write_file, list_files
                     _ => {
+                        let tool_desc = match tc.function.name.as_str() {
+                            "execute" => {
+                                let cmd_preview = args.get("command").and_then(|v| v.as_str()).unwrap_or("").chars().take(60).collect::<String>();
+                                format!("执行命令: {}", cmd_preview)
+                            }
+                            "read_file" => format!("读取文件: {}", args.get("path").and_then(|v| v.as_str()).unwrap_or("?")),
+                            "write_file" => format!("写入文件: {}", args.get("path").and_then(|v| v.as_str()).unwrap_or("?")),
+                            "list_files" => "列出文件".to_string(),
+                            other => format!("工具: {}", other),
+                        };
+                        let _ = broadcast_tx.send(WsMessage::ActivityUpdate {
+                            workflow_id: workflow_id.to_string(),
+                            activity: format!("步骤 {} — {}", step_order, tool_desc),
+                        });
                         let result = execute_tool(&tc.function.name, &tc.function.arguments, workdir, exec).await;
                         let status = if result.starts_with("Error:") { "failed" } else { "done" };
                         log_execution(pool, broadcast_tx, workflow_id, step_order, &tc.function.name, &tc.function.arguments, &result, status).await;
@@ -1492,6 +1519,10 @@ async fn run_agent_loop(
         let tool_count = planning_tools.len() as i32;
 
         tracing::info!("[workflow {}] Planning LLM call #{} msgs={}", workflow_id, iteration + 1, messages.len());
+        let _ = broadcast_tx.send(WsMessage::ActivityUpdate {
+            workflow_id: workflow_id.to_string(),
+            activity: "规划中 — 等待 LLM 响应...".to_string(),
+        });
         let call_start = std::time::Instant::now();
         let response = match llm.chat_with_tools(messages, &planning_tools).await {
             Ok(r) => r,
@@ -1702,6 +1733,10 @@ async fn run_agent_loop(
         state.current_step_chat_history.clear();
 
         tracing::info!("[workflow {}] Coordinator review for step {}", workflow_id, step_order);
+        let _ = broadcast_tx.send(WsMessage::ActivityUpdate {
+            workflow_id: workflow_id.to_string(),
+            activity: format!("步骤 {} 完成 — 协调器审核中...", step_order),
+        });
         let call_start = std::time::Instant::now();
         let coord_response = match llm.chat_with_tools(coord_messages.clone(), &coordinator_tools).await {
             Ok(r) => r,