Fix unhandled exception in request handling crashes the process

[iaohkut-from-NightWolf-Team]

Fixes #150.

Summary

getOutputDirFilePath() throws Error("Invalid path") as its normal rejection path for an out-of-bounds request, but nothing in the call chain up to the raw http.Server request handler caught it. Since onRequestHandler is async, the thrown error becomes a rejected promise with no .catch() attached by the caller — an unhandled rejection that terminates the entire Node.js process on a single crafted GET request.

Fix

Wrap the middleware-chain invocation in onRequestHandler in a try/catch and respond with a normal 400 instead of letting the exception escape:

let [first] = bound;
try {
  await first();
} catch(e) {
  if(!res.headersSent) {
    res.statusCode = 400;
    res.end("Bad Request");
  }
}

Verification

• Full existing test suite: 32/32 passing, no regressions.
• PoC that previously crashed the server with a single request now returns 400, and the server stays alive for subsequent requests:

  $ curl http://localhost:PORT/%2e%2e%2fsecret.txt
  # before: process crashes, subsequent requests get connection refused
  # after:  HTTP 400, server stays up
  

See #150 for the full report and original reproduction.