让 AI 以资深工程师视角审查代码，逐条列出问题位置、原因、影响与修复代码片段，并按严重程度排序。

Review this code with the eye of a senior engineer who cares about shipping reliable software: ``` [paste code] ``` For each issue found, provide: 1. The exact line or section 2. What the problem is 3. Why it matters (bug? perf? security? maintenance?) 4. The fix, as a code snippet Prioritize by severity.