v0.1.3

This release cleans up the client lifecycle so it can run under systemd or another supervisor without daemonizing itself.

What changed

• Handle SIGINT and SIGTERM through one application context.
• Cancel API polling, nomination waits, reconnect backoff, and tunnel supervision promptly.
• Return operational errors to the CLI instead of exiting deep inside the connection workflow.
• Stop and join tunnel workers, candidate probes, and the SOCKS5 serving goroutine during shutdown.
• Add tests for canceled polling, in-flight HTTP cancellation, and nomination shutdown.

The binary remains a foreground process; the service manager owns restart policy, logging, and boot persistence.