diagnostics: System → Diagnostics with a network test probe; RTP_PORT_START/END

The server checks itself (public IP, DNS, local networks, phone ACL, SIP transports, free audio
ports) and says how to fix each problem. A quick or complete network test asks the probe
(apps/probe, own image) to test this server from outside: HTTP/HTTPS, SIP over UDP/TCP/TLS, the
browser phone's /ws, sampled audio ports. The probe only tests the address that asks.
The audio port range comes from RTP_PORT_START/END (default 10000-20000).

apps/api/src/generator/load.ts

@@ -203,8 +203,12 @@ export type Snapshot = {
   mohClasses: string[];
   /** Played before recording a call that a phone number records (Settings → Recording). */
   recordingAnnouncement: string | null;
+  /** Call audio ports from the environment (RTP_PORT_START/END), not the database. */
+  rtpPorts?: { start: number; end: number };
 };
 
+export const DEFAULT_RTP_PORTS = { start: 10000, end: 20000 };
+
 export function todayIn(timezone: string, now = new Date()): string {
   // en-CA formats as YYYY-MM-DD.
   return new Intl.DateTimeFormat('en-CA', { timeZone: timezone }).format(now);