The bare `t3 serve` behind Authentik showed the manual /pair#token screen, which
didn't connect. Mirror the devvm t3-dispatch: a small stdlib-Node sidecar fronts
t3 serve, and on a cookieless (already Authentik-gated) document load it mints a
pairing credential (`t3 auth pairing create`) and exchanges it at
/api/auth/browser-session for the t3_session cookie, then 302s back. Everything
else — including WebSocket upgrades for the live cockpit — reverse-proxies to
:3773. The Service now targets the sidecar (:8080).
Verified: cookieless GET -> 302 + Set-Cookie t3_session; cookied GET -> 200 SPA.
Matches the t3.viktorbarzin.me experience (Authentik login -> straight into the
cockpit).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
