🐛 Cloudflared metrics return 1 HA connection when there are none. #1633

Describe the bug

The cloudflared metrics endpoint (/metrics) reports cloudflared_tunnel_ha_connections 1 even though no QUIC connections to the Cloudflare edge have been successfully established. All connection attempts are failing with timeout: no recent network activity, yet the cloudflared_tunnel_ha_connections gauge incorrectly shows 1 active HA connection instead of 0.

To Reproduce

Steps to reproduce the behavior:

1. Configure a Cloudflare Tunnel using a tunnel token (remotely managed) with metrics enabled on 0.0.0.0:7013
2. Start cloudflared in an environment where QUIC connections to the Cloudflare edge time out (e.g., firewall blocking UDP to Cloudflare edge IPs)
3. Observe repeated ERR Failed to dial a quic connection errors in the logs — no connection is ever successfully established
4. Query the metrics endpoint at http://<host>:7013/metrics
5. Observe that cloudflared_tunnel_ha_connections reports 1 despite zero successful connections

Expected behavior

When all QUIC connection attempts to the Cloudflare edge fail and no tunnel connections are active, the metric cloudflared_tunnel_ha_connections should report 0, not 1. The gauge should only increment once a connection is successfully established, and should accurately reflect the number of active HA connections at any given time.

Environment and versions

Additional context

This machine would have had access to port cloudflare services on 80:443, but not the additional ports used, e..g 7844