fix: audit findings — test compilation, artifact pipeline, typo

- C-1: Add event_sender: None to ToolContext in file_write.rs and
  file_read.rs test helper functions (compilation fix)
- I-1: file_write tool now echoes content preview in output JSON,
  enabling streamStore.ts artifact auto-creation pipeline to work
- S-2: Fix typo "LLM 锥应错误" → "LLM 响应错误" in loop_runner.rs

crates/zclaw-runtime/src/loop_runner.rs

@@ -744,7 +744,7 @@ impl AgentLoop {
                         }
                         Ok(Some(Err(e))) => {
                             tracing::error!("[AgentLoop] Chunk error: {}", e);
-                            let _ = tx.send(LoopEvent::Error(format!("LLM 锥应错误: {}", e.to_string()))).await;
+                            let _ = tx.send(LoopEvent::Error(format!("LLM 响应错误: {}", e.to_string()))).await;
                             stream_errored = true;
                         }
                         Ok(None) => break, // Stream ended normally

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

@@ -140,6 +140,7 @@ mod tests {
             session_id: None,
             skill_executor: None,
             path_validator,
+            event_sender: None,
         };
 
         let tool = FileReadTool::new();

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

@@ -119,11 +119,24 @@ impl Tool for FileWriteTool {
         file.write_all(&bytes)
             .map_err(|e| ZclawError::ToolError(format!("Failed to write file: {}", e)))?;
 
+        // Echo content preview in output for artifact auto-creation in frontend
+        let content_preview: String = if content.len() <= 5000 {
+            content.to_string()
+        } else {
+            let truncation_point = content.char_indices()
+                .take_while(|(i, _)| *i < 5000)
+                .last()
+                .map(|(i, c)| i + c.len_utf8())
+                .unwrap_or(5000.min(content.len()));
+            format!("{}...[truncated, {} total bytes]", &content[..truncation_point], content.len())
+        };
+
         Ok(json!({
             "success": true,
             "bytes_written": bytes.len(),
             "path": validated_path.to_string_lossy(),
-            "mode": mode
+            "mode": mode,
+            "content": content_preview
         }))
     }
 }
@@ -150,6 +163,7 @@ mod tests {
             session_id: None,
             skill_executor: None,
             path_validator,
+            event_sender: None,
         }
     }