Apple TV can't be signed in from a nearby iPhone after Sign Out or an expired session

[Quick104]

A nearby iPhone or iPad only offers to set up an Apple TV that is on its first-run server-setup screen. After Sign Out (keeping the server) or an expired session, the Apple TV shows its sign-in screen instead, and no phone offers to sign it back in. The only ways back are scanning the QR code, which opens the web approval page and needs a separate web sign-in, or typing a password with the remote.

Why

• Only TVServerSetupView runs the pairing advertiser (TVServerSetupView.swift). TVLoginView doesn't advertise.
• The login receiver state is marked "RESERVED, NOT IMPLEMENTED" (PairingProtocol.swift).
• The phone card only offers TVs whose state is .setup (CompanionPairingCardModifier.swift).
• Sign Out without removing the server, and an expired session, both go to .needsLogin (sign out, expired session).

Expected

With Silo open on a signed-in iPhone or iPad on the same network, a signed-out Apple TV on its sign-in screen gets the same offer: sign it in, confirm the code, approve. The phone offers it only when it holds the server the TV is signed out of, and skips the server chooser.

Notes

• The companion pairing design already describes this as the st=login flow (docs/superpowers/specs/2026-06-14-companion-pairing-design.md).
• The phone has to know which server the TV wants, so the TV's TXT record or hello needs to carry the server identity from GET /api/v2/system/identity. That is an additive protocol change.
• Android TV has the same gap (Android TV can't be signed in from a nearby phone after its session expires silo-android#419). Android TV advertises only setup because advertising login made it invisible to iPhones, whose card filters to .setup. The phone side here has to accept login TVs before either TV starts advertising it.
• Related issue: [v1] TV client sign-in & onboarding silo-server#1192. Its AC2 covers TVs awaiting setup; this extends the same offer to signed-out TVs.

AI disclosure

• Harness: T3 Code (Claude Code agent harness)
• Tool(s): Claude Code, GitHub CLI
• Model(s): claude-opus-5-5
• Involvement: AI-drafted at the maintainer's request, from reading the code on main at bb4f4a5; not reproduced on a device
• Adversarial review: n/a