Add explicit -u/--unix flag to force UNIX socket transport

[jeonghanlee]

Add explicit -u/--unix flag to force UNIX socket transport

Milestone

Backlog

Labels

enhancement, P3-low, area/uds

Summary

con infers UNIX-vs-TCP transport from a colon heuristic. Comparable tools select transport explicitly (socat UNIX-CONNECT:/path / TCP:host:port, ncat -U). Add a -u/--unix flag that forces AF_UNIX and bypasses the colon heuristic, giving a deterministic override for paths the heuristic cannot classify (for example a slashless relative socket name with a numeric-looking suffix, cache:6379).

Proposed Fix

Add -u/--unix to the option loop; when set, treat the target as a UNIX socket path at the client and server split sites regardless of any colon.

Acceptance Criteria

• con -u -c <path> connects as a UNIX socket even when <path> contains a colon and a numeric tail.
• Help text documents the flag and the heuristic it overrides.

Out of Scope

Changing the flagless heuristic (that is the M1/#4 fix). This issue is purely additive.

Surfaced during the M1 (#4) review session, 2026-06-22; kept out of #4 to hold the P1 fix to the size of the bug.