BEFORE | commit fc2b5de20cb572d2333e03284466e3c804d25c84
Environment: Linux, Node v26.12.1, real Tailscale Serve, fresh isolated T3 home; no seeded data.
$ T3CODE_DEV_SEED=0 vp run dev --share --built --host localhost
Listening on http://[::1]:15862
$ tailscale serve status --json  # selected route; hostname redacted
https://<tailnet-host>:7822/ -> http://127.0.0.1:15862
$ ss -H -ltn (selected backend port)
LISTEN 0      511    [::1]:15862 [::]:*
$ curl --noproxy "*" -sS -o /dev/null -w "HTTP %{http_code}" http://127.0.0.1:15862/
HTTP 000; curl exit 7
curl: (7) Failed to connect to 127.0.0.1 port 15862 after 0 ms: Couldn't connect to server
$ curl --noproxy "*" -sS -o /dev/null -w "HTTP %{http_code}" http://[::1]:15862/
HTTP 302; curl exit 0
$ curl --noproxy "*" -sS -D headers -o body https://<tailnet-host>:7822/
HTTP/2 502 ; curl exit 0
Response body: empty
$ curl --noproxy "*" -sS -D headers -o body https://<tailnet-host>:7822/pair
HTTP/2 502 ; curl exit 0
Response body: empty