DEFAULT_HANDSHAKE_TIMEOUT

Default ceiling on one connection's Nearby handshake.

Deliberately not us.tractat.kuilt.core.LoomDefaults.WEAVE_TIMEOUT, despite carrying the same number today. A weave timeout bounds a whole rendezvous — discovery, dialling and handshake — and this one cannot: on the discoverer path NearbyApi.startDiscovery and the wait for the first EndpointFound complete before the clock starts, and on the advertiser path weave has already returned its seam, so nothing the ceiling covers can fail a weave call at all. Naming it weaveTimeout would promise a bound on weave that no path delivers (#1430). It belongs with the handshakeTimeout family — a ceiling on a single connection — and moves independently of the shared rendezvous default.