fix: spawn node not bun for bash node commands on Windows

Bun's event loop exits after top-level await resolves, killing
long-running servers. Use actual node binary which keeps the
event loop alive for http.listen().

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: lanmower

src/runtime.js

@@ -70,7 +70,7 @@ export function spawnProcess(runtime, code, cwd) {
       const parts = code.match(/^\s*cd\s+(\S+)\s*&&\s*node\s+(.+)$/);
       const nodeCwd = parts ? parts[1].replace(/['"]/g, '') : cwd;
       const nodeArgs = (parts ? parts[2] : nodeMatch[1]).trim().split(/\s+/);
-      const child = spawn('bun', nodeArgs, spawnOpts(nodeCwd || cwd));
+      const child = spawn('node', nodeArgs, spawnOpts(nodeCwd || cwd));
       return { child, cleanup };
     }
     if (IS_WIN) {