* feat(mobile): mount ProtocolBlockScreen when protocol compat is blocked
ProtocolBlockScreen existed since PR #1440 but was never mounted: on a
'blocked' compat verdict the only output was a console.warn, so a future
MIN_COMPATIBLE_RUNTIME_CLIENT_VERSION bump would have silently shown a
broken host UI instead of the update screen.
Add HostProtocolGate — a choke point in app/h/_layout.tsx above every
/h/[hostId] route — that consumes useHostStatusGates and replaces the
blocked host's entire UI (sidebar + detail stack) with ProtocolBlockScreen.
The host list and other hosts stay usable; the screen's own 'Back to
hosts' escape hatch routes to '/'. Both block reasons render their
respective CTAs (mobile-too-old → App Store, desktop-too-old → GitHub
Releases). Compat logic stays in the src/shared mirror contract — no fork.
* fix(mobile): fence incompatible host routes efficiently
* fix(mobile): route Android updates to releases
405b9f245a