Real T3 Code server: before
Commit: fc2b5de20cb572d2333e03284466e3c804d25c84
Environment: Linux; fresh isolated T3 home for each state; real sshd on port 22.
Only the tailscale executable is substituted with synthetic status/prefs.
No provider turns or copied user data.
Privacy: OS mDNS hostname is shown as editor-host.local; usernames are omitted.

Live SSH banner: SSH-2.0-OpenSSH_9.6p1 Ubuntu-3ubuntu13.16

Step 1: tailscale up (synthetic CLI state: Running)
status --json: {"BackendState": "Running", "Self": {"DNSName": "editor-host.tail1234.ts.net.", "TailscaleIPs": ["100.64.1.2"], "Online": true}}
debug prefs: {"WantRunning": true, "RunSSH": false}
server.getConfig remoteOpenTargets: [
  {
    "kind": "tailscale",
    "host": "editor-host.tail1234.ts.net"
  },
  {
    "kind": "mdns",
    "host": "editor-host.local"
  }
]

Step 2: tailscale down (synthetic CLI state: Stopped)
status --json: {"BackendState": "Stopped", "Self": {"DNSName": "editor-host.tail1234.ts.net.", "TailscaleIPs": ["100.64.1.2"], "Online": false}}
debug prefs: {"WantRunning": false, "RunSSH": false}
server.getConfig remoteOpenTargets: [
  {
    "kind": "tailscale",
    "host": "editor-host.tail1234.ts.net"
  },
  {
    "kind": "mdns",
    "host": "editor-host.local"
  }
]

Step 3: tailscale up (synthetic CLI state: Running)
status --json: {"BackendState": "Running", "Self": {"DNSName": "editor-host.tail1234.ts.net.", "TailscaleIPs": ["100.64.1.2"], "Online": true}}
debug prefs: {"WantRunning": true, "RunSSH": false}
server.getConfig remoteOpenTargets: [
  {
    "kind": "tailscale",
    "host": "editor-host.tail1234.ts.net"
  },
  {
    "kind": "mdns",
    "host": "editor-host.local"
  }
]

Observed: BUG: stopped Tailscale is still advertised first.
Recovery: tailnet target returns while Running.