Unix Domain Sockets / Named Pipes

> ℹ️ _This issue was partially AI-generated and may contain technical inaccuracies._

**Is your feature request related to a problem? Please describe.**
Services exposed only over a local Unix domain socket or named pipe (common for containerized/local daemons) cannot be reached, since requests assume a TCP port.

**Describe the solution you'd like**
Allow sending requests over a Unix domain socket (or Windows named pipe) instead of a TCP host:port.

**Describe alternatives you've considered**
Running a local TCP proxy in front of the socket.

**Additional context**
Postman-exclusive feature. Useful for debugging containerized or local services that don't expose a port.

Start by tracing the request path that currently assumes a TCP host and port; the issue does not name a file or test to begin with. Define how Unix domain sockets and Windows named pipes should be selected and exercised, with completion covering requests to both endpoint types without requiring a TCP proxy.

Written by the indexing model from the issue text.