contacts: caller names on desk phones while they ring (C4)

Spec 11 §6.1: sp-sub-dial-user asks /api/internal/caller-name (func_curl, 2 s at most; this
machine only, with an APP_SECRET-derived key, not logged) for the ringing user's name for the
caller, and sets it on each ringing leg (pre-dial handler, CONNECTEDLINE), never on the call, so
forwards and other members don't see someone else's contacts. Ring group/queue/number prefixes
kept. Contrack lookups never wait (cache, contactsWarm every 5 min). Proven on real Asterisk
with baresip: apps/api/test/asterisk/cnam-test.ts.

apps/api/src/generator/load.ts

@@ -205,6 +205,8 @@ export type Snapshot = {
   recordingAnnouncement: string | null;
   /** Call audio ports from the environment (RTP_PORT_START/END), not the database. */
   rtpPorts?: { start: number; end: number };
+  /** Caller names on ringing phones (11 §6 C4): the api's lookup URL and its key. */
+  callerNames?: { url: string; token: string };
 };
 
 export const DEFAULT_RTP_PORTS = { start: 10000, end: 20000 };