HostRuntime self-boots via boot() and emits state through existing
subscribeAll plumbing. DaemonStartService runs in parallel: on success
it upserts the connection, which HostRuntime's syncHosts already wires
into a controller; on failure it emits an error.
The bootstrap no longer awaits daemon-start before letting saved-host
controllers connect. index.tsx resolves the redirect from
useEarliestOnlineHostServerId + useDaemonStartLastError subscriptions,
not from a procedural promise. The splash error is derived state:
splashError = !anyOnlineHostServerId ? daemonStartError : null. Retry
calls only DaemonStartService.start().
Deletes initializeHostRuntime, setupDesktopManagedConnection,
addConnectionFromListenAndWaitForOnline, bootstrapDesktop on the store,
waitForAnyConnectionOnline (now unused in production), and the
phase enum. Net -623 lines.
