* feat(xray): add tunnel health monitor
* fix(tunnelmonitor): reuse netproxy client and init logger in tests
Replace the duplicated newHTTPClient/dialContextWithProxy with netproxy.NewHTTPClient, which centralises the http/https/socks5 handling and avoids the dial-goroutine connection leak on context cancellation. Cap failures at the threshold during cooldown so the counter stays a true consecutive-failure count. Add TestMain to initialise the logger and fix the nil-pointer panic in the success-after-failure path.
* fix(tunnelmonitor): observable recovery, signal headroom, and hardening
Address the remaining review findings on the tunnel health monitor:
- Recovery is now synchronous and observable: the callback calls
server.RestartXray() directly and returns its error instead of just
enqueuing SIGUSR1, so a failed restart no longer masks as success and
arms the cooldown while the tunnel is still down.
- Give the OS signal channel headroom (buffer 8) so producers cannot
starve a SIGTERM/SIGINT out of the single slot.
- Warn at startup when the monitor is enabled without a proxy, since the
probe then measures host connectivity rather than the xray tunnel.
- Cap failures at the threshold in the nil-recover branch too, matching
the cooldown cap.
- Document the XUI_TUNNEL_HEALTH_* vars in .env.example and the README.
- Add tests for status-code classification, Normalize bounds, New proxy
scheme errors, the recovery-error and nil-recover paths, the cooldown
cap, and Run context cancellation (coverage 90%).
---------
Co-authored-by: Sanaei <ho3ein.sanaei@gmail.com>
MHSanaei