Cloudflare Request and response attribute asymmetry against Deno

`wrapRequestHandlerWithInit` does not do two things `wrapDenoRequestHandler` does:

* set response headers as span attributes via `httpHeadersToSpanAttributes(..., 'response')`
* set `isolationScope.setContext('response', { status_code })`

**Work item.** Decide which behavior is correct and make the two match. If Cloudflare deliberately skips response headers for payload-size reasons, say so in a comment.

Start by locating wrapRequestHandlerWithInit and wrapDenoRequestHandler, then compare their response handling, including httpHeadersToSpanAttributes and isolationScope.setContext. Decide which behavior should be shared; done means both handlers match, with a comment if Cloudflare intentionally omits response headers for payload-size reasons.

Written by the indexing model from the issue text.