chore: import upstream snapshot with attribution

internal/sshurl/sshurl.go

@@ -0,0 +1,60 @@
+// Package sshurl parses ssh:// URLs into components for use with the ssh binary.
+package sshurl
+
+import (
+	"fmt"
+	"net"
+	"net/url"
+)
+
+// Parsed holds the components of an ssh:// URL.
+type Parsed struct {
+	Host string // hostname or user@hostname
+	Port string // port number, or "" for default
+	Path string // absolute remote path (starts with /)
+}
+
+// SSHArgs returns the ssh command arguments for connecting to this host.
+// If a port is specified, -p is included.
+func (p Parsed) SSHArgs() []string {
+	args := []string{"-o", "BatchMode=yes", "-o", "StrictHostKeyChecking=yes", "-o", "ConnectTimeout=5"}
+	if p.Port != "" {
+		args = append(args, "-p", p.Port)
+	}
+	args = append(args, p.Host)
+	return args
+}
+
+// Parse parses an ssh:// URL into host, port, and path components.
+// Accepts formats like ssh://host/path, ssh://user@host/path, ssh://host:2222/path.
+func Parse(raw string) (Parsed, error) {
+	u, err := url.Parse(raw)
+	if err != nil {
+		return Parsed{}, fmt.Errorf("invalid ssh URL %q: %w", raw, err)
+	}
+	if u.Scheme != "ssh" {
+		return Parsed{}, fmt.Errorf("expected ssh:// scheme, got %q", u.Scheme)
+	}
+	if u.Path == "" {
+		return Parsed{}, fmt.Errorf("ssh URL missing path: %s", raw)
+	}
+
+	host := u.Hostname()
+	if u.User != nil {
+		host = u.User.Username() + "@" + host
+	}
+
+	port := u.Port()
+	// net/url splits host:port correctly; verify with SplitHostPort for edge cases.
+	if port == "" && u.Host != host {
+		if _, p, err := net.SplitHostPort(u.Host); err == nil {
+			port = p
+		}
+	}
+
+	return Parsed{
+		Host: host,
+		Port: port,
+		Path: u.Path,
+	}, nil
+}