Closing this WIP PR — it's over 4 years old and far too stale to merge against the current codebase.

The valuable takeaway from this experiment: supporting alternative HTTP clients by exposing send_request_metric_to_parent and manually constructing GooseRequestMetric structs is brittle and requires too much boilerplate (the util.rs helper alone was 111 lines). This confirms that Goose is deeply coupled to Reqwest throughout the request/response pipeline, cookie handling, metrics collection, and error types.

The architectural discussion for a proper solution continues in #32. A good abstraction will need to account for cookies, connection pooling, metrics collection, and coordinated omission tracking — not just swapping out the HTTP client.