refactor(cli): use AbortController for HTTP timeout handling

Replace req.destroy() timeout handling with AbortController pattern
for cleaner resource cleanup. This ensures proper cleanup of buffered
response data on timeout and follows modern Node.js best practices.

Changes:
- Create AbortController with signal passed to request options
- Use setTimeout to trigger abort after timeout period
- Clear timeout on successful completion or error
- Handle AbortError in error handler for timeout messages

Author: NikolayS

cli/lib/checkup-api.ts

@@ -157,18 +157,23 @@ async function postRpc<T>(params: {
     "Content-Length": Buffer.byteLength(body).toString(),
   };
 
+  // Use AbortController for clean timeout handling
+  const controller = new AbortController();
+  const timeoutId = setTimeout(() => controller.abort(), timeoutMs);
+
   return new Promise((resolve, reject) => {
     const req = https.request(
       url,
       {
         method: "POST",
         headers,
-        timeout: timeoutMs,
+        signal: controller.signal,
       },
       (res) => {
         let data = "";
         res.on("data", (chunk) => (data += chunk));
         res.on("end", () => {
+          clearTimeout(timeoutId);
           if (res.statusCode && res.statusCode >= 200 && res.statusCode < 300) {
             try {
               const parsed = JSON.parse(data);
@@ -189,16 +194,19 @@ async function postRpc<T>(params: {
             reject(new RpcError({ rpcName, statusCode, payloadText: data, payloadJson }));
           }
         });
+        res.on("error", () => {
+          clearTimeout(timeoutId);
+        });
       }
     );
 
-    // Handle timeout event
-    req.on("timeout", () => {
-      req.destroy();
-      reject(new Error(`RPC ${rpcName} timed out after ${timeoutMs}ms`));
-    });
-    
     req.on("error", (err: Error) => {
+      clearTimeout(timeoutId);
+      // Handle abort as timeout
+      if (err.name === "AbortError" || (err as any).code === "ABORT_ERR") {
+        reject(new Error(`RPC ${rpcName} timed out after ${timeoutMs}ms`));
+        return;
+      }
       // Provide clearer error for common network issues
       if ((err as any).code === "ECONNREFUSED") {
         reject(new Error(`RPC ${rpcName} failed: connection refused to ${url.host}`));