extract proxying into a middleware instead of a fallback handler

Cargo.lock

@@ -6315,11 +6315,13 @@ dependencies = [
  "dotenvy",
  "ed25519-dalek",
  "futures",
+ "futures-util",
  "governor",
  "hex",
  "hickory-resolver",
  "hkdf",
  "hmac",
+ "http 1.4.0",
  "image",
  "ipld-core",
  "iroh-car",
@@ -6352,7 +6354,9 @@ dependencies = [
  "tokio",
  "tokio-tungstenite",
  "totp-rs",
+ "tower",
  "tower-http",
+ "tower-layer",
  "tracing",
  "tracing-subscriber",
  "urlencoding",