应用专业编辑审查：修复版本/引用/技术准确性等 3 处

19_observability/19.3_performance_optimization.md

@@ -323,7 +323,8 @@ journalctl -u docker -n 100 | grep -i "oom"
 FROM python:3.14-slim
 WORKDIR /app
 COPY requirements.txt .
-RUN pip install -r requirements.txt memory_profiler tracemalloc
+# tracemalloc 是 Python 标准库模块（自 3.4 起内置），无需安装
+RUN pip install -r requirements.txt memory_profiler
 
 COPY app.py .
 CMD ["python", "-m", "memory_profiler", "app.py"]