Foreman » Smart Proxy

Introduce a shared Faraday-based outbound transport for smart-proxy requests to Foreman or Satellite.

This replaces the current per-request Net::HTTP transport path with a shared client layer that supports persistent upstream connections, preserves the existing request-building API, and adds cleaner seams for future TLS and PQC-related transport changes.

The work includes:
- shared outbound Foreman transport ownership
- persistent connections via faraday-net_http_persistent
- transport identity and cache reset behavior
- layered connect and read timeout support
- focused request transport test coverage

This is intended to reduce repeated Capsule to Satellite connection setup and prepare the code for future PQC transport changes.