Make request path, body, and header semantics consistent across JS and native

[yorkin-bot]

Summary

The JS and native adapters currently construct materially different HttpRequest values for the same HTTP request.

Relevant code:

• native strips the query string before dispatch
• native reads bodies for POST, PUT, PATCH, and framed requests
• JS routes against the raw Node req.url
• JS reads a body only when the method is exactly POST
• public headers are a case-sensitive Map[StringView, StringView]

Confirmed differences

Query strings

With a registered GET /hello route:

• native: GET /hello?x=1 returns 200, but the handler receives only /hello and cannot recover the query;
• JS: GET /hello?x=1 returns 404 because routing uses the raw /hello?x=1.

PUT/PATCH bodies

An echo handler receives the request body on native. On JS, both PUT and PATCH have an empty raw_body because only POST subscribes to the Node data/end events.

Header casing

A handler using event.req.headers.get("X-Test") produced:

• JS: missing whether the client sent x-test or X-Test (Node normalizes keys to lowercase);
• native: value found only when the wire casing was exactly X-Test.

HTTP field names are case-insensitive, so application behavior must not depend on client casing or backend.

Expected behavior

Define one backend-independent request contract:

• route using a parsed path, while retaining the query separately;
• read framed bodies consistently for all applicable methods;
• use an owned, case-insensitive header abstraction;
• add the same request-conformance suite against JS and native adapters.

The exact public shape could be path + query, a parsed URI, or an explicit raw target, but handlers should receive equivalent information on both backends.

[oboard]

feat: unify the HTTP request contract across backends#28