netbird-server: drop vestigial reverse-SSH tunnel

The netbird-tunnel.service.j2 reverse-SSH tunnel template was never
instantiated by any task in the role, and its target
netbird_auth_ingress_host=10.2.45.100 was the Caddy HA keepalived VIP,
destroyed in PR #70. The VPS reaches homelab auth over the NetBird mesh
now (netbird-ingress DaemonSet -> Traefik fd99::86), so the tunnel is
dead. Remove the template and its only-consumer vars
(netbird_auth_tunnel_port/ingress_host/ingress_port, netbird_tunnel_ssh_key).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

ansible/roles/netbird-server/defaults/main.yml

@@ -16,14 +16,6 @@ netbird_auth_audience: "qrCjbsFeOO32kXOVwF8OrunzettalsMJ5GoOKJAR"
 netbird_auth_client_id: "qrCjbsFeOO32kXOVwF8OrunzettalsMJ5GoOKJAR"
 netbird_auth_client_secret: "{{ vault_netbird_auth_client_secret }}"
 netbird_auth_issuer: "https://auth.renner.uno/application/o/netbird/"
-netbird_auth_tunnel_port: 8443
-
-# Homelab ingress for tunnel
-netbird_auth_ingress_host: "10.2.45.100"
-netbird_auth_ingress_port: 443
-
-# Tunnel SSH key path (on tunnel host)
-netbird_tunnel_ssh_key: "/root/.ssh/netbird_tunnel_key"
 
 # TURN server credentials
 netbird_turn_secret: "{{ vault_netbird_turn_secret }}"

ansible/roles/netbird-server/templates/netbird-tunnel.service.j2

@@ -1,28 +0,0 @@
-[Unit]
-Description=NetBird Auth SSH Tunnel (autossh)
-Documentation=https://netbird.io
-After=network-online.target
-Wants=network-online.target
-
-[Service]
-Type=simple
-Environment="AUTOSSH_GATETIME=0"
-Environment="AUTOSSH_POLL=30"
-Environment="AUTOSSH_LOGLEVEL=7"
-
-# Reverse tunnel: VPS:{{ netbird_auth_tunnel_port }} -> homelab ingress:{{ netbird_auth_ingress_port }}
-# This allows VPS containers to reach auth.renner.uno via localhost:{{ netbird_auth_tunnel_port }}
-ExecStart=/usr/bin/autossh -M 0 -N \
-    -o "ServerAliveInterval=30" \
-    -o "ServerAliveCountMax=3" \
-    -o "ExitOnForwardFailure=yes" \
-    -o "StrictHostKeyChecking=accept-new" \
-    -i {{ netbird_tunnel_ssh_key }} \
-    -R {{ netbird_auth_tunnel_port }}:{{ netbird_auth_ingress_host }}:{{ netbird_auth_ingress_port }} \
-    {{ netbird_server_user }}@{{ netbird_server_host }}
-
-Restart=always
-RestartSec=10
-
-[Install]
-WantedBy=multi-user.target