## What changed
- Add `HttpClientBuilder` for configuring default headers, redirects, the
Cloudflare cookie store, and request diagnostics without exposing the
underlying transport.
- Provide factory-backed construction for fixed destinations that respects
outbound proxy policy, alongside explicit direct and legacy
transport-default construction paths.
- Preserve the request-logging setting in `ReqwestTransport`, so disabling
diagnostics also suppresses transport-level URL and request-body traces.
- Add `HEAD`, `DELETE`, and query-parameter helpers to the shared client
wrappers.
## Testing
- Verify builder configuration survives policy-aware construction and custom
CA fallback.
- Verify disabled request logging omits request URLs and bodies from transport
traces.
GitOrigin-RevId: 529c33abefeb88f38ff9a0ead374d29fcc872e6a
Michael Bolin
adb143a291