fix: 修复未处理的Promise拒绝和文件流错误导致的进程崩溃

- 添加全局异常捕获（uncaughtException, unhandledRejection）防止进程意外退出
- 修复请求合并逻辑中Promise链处理不当导致的Unhandled Promise Rejection
- 为文件读取流添加错误监听，防止文件系统异常导致进程崩溃
- 更新README.md文档以反映稳定性修复
- 将*.log添加到.gitignore忽略日志文件

server.js

@@ -6,6 +6,15 @@ const path = require('path');
 const crypto = require('crypto');
 const net = require('net');
 
+// 全局错误捕获，防止进程退出
+process.on('uncaughtException', (err) => {
+  console.error('[FATAL] Uncaught Exception:', err);
+});
+
+process.on('unhandledRejection', (reason, promise) => {
+  console.error('[FATAL] Unhandled Rejection:', reason);
+});
+
 require('dotenv').config();
 const app = express();
 const PORT = Number(process.env.PORT) || 11489;
@@ -301,6 +310,10 @@ async function handleProxyRequest(res, upstreamUrl, targetUrl) {
         }
         
         const stream = fs.createReadStream(dataPath);
+        stream.on('error', (streamErr) => {
+           console.error(`[stream-error] ${streamErr.message}`);
+           if (!res.headersSent) res.end();
+        });
         stream.pipe(res);
         return;
       } else {
@@ -319,13 +332,12 @@ async function handleProxyRequest(res, upstreamUrl, targetUrl) {
         console.log(`[coalesce-hit] joining pending request for ${upstreamUrl}`);
         resultPromise = pendingRequests.get(key);
     } else {
-        resultPromise = fetchAndCache(upstreamUrl, targetUrl, key);
+        // 创建 Promise 链，确保 finally 包含在内，防止 Unhandled Rejection
+        resultPromise = fetchAndCache(upstreamUrl, targetUrl, key)
+            .finally(() => {
+                pendingRequests.delete(key);
+            });
         pendingRequests.set(key, resultPromise);
-        
-        // 无论成功失败，结束后移除 map
-        resultPromise.finally(() => {
-            pendingRequests.delete(key);
-        });
     }
 
     const result = await resultPromise;
@@ -353,6 +365,10 @@ async function handleProxyRequest(res, upstreamUrl, targetUrl) {
         res.set('Cache-Control', 'public, max-age=315360000, immutable');
         res.type(meta.contentType);
         const stream = fs.createReadStream(dataPath);
+        stream.on('error', (streamErr) => {
+           console.error(`[stream-error] ${streamErr.message}`);
+           if (!res.headersSent) res.end();
+        });
         stream.pipe(res);
         return;
       }