Description

Refactors request handling in the App class so the loop and handle closures are no longer allocated on every incoming request.
code extracted into private methods (#loop and #handle) with a small explicit state object.

Benefits

• Reduces per-request closure allocations (2 fewer function objects created per request).

Benchmarks

• Tested on my machine (Apple Silicon, Node v24.16.0 wrk -t4 -c64 -d10s, hello-world route).
• throughput is the same as master (~83k req/s on both, within run-to-run noise).
• and GC counts under a fixed 500k-request load are essentially identical.

PS

• So this PR doesn't make the performance of the application faster than current code.