cdfad420bb
Extract the TLS-without-CA guard into a shared `build_tls_config` helper in options.rs so both GatewayClient and GalaxyClient use identical logic. GalaxyClient previously had no guard, so TLS-without-CA produced a cryptic tonic handshake failure; it now returns the same actionable InvalidEndpoint error. The guard message notes that a server-name override affects SNI but does not pin trust. Add --require-certificate-validation to ConnectionArgs in the CLI binary. Add a mirror test for GalaxyClient in tests/tls.rs.