announcements: play a sound, then continue

/api/announcements CRUD (sound must be a prompt, destination must exist
and not be itself, delete refused while referenced); the generator
renders sp-ann-{id} (Answer, Playback, destApp) and destApp sends
announcement destinations there. The ivr golden case gains "press 3:
hours announcement, then back to the menu". Announcements are managed in
a section of Sounds & music (05 updated); the DestinationPicker gains
"Announcement".

Task: M6-T5

apps/api/src/generator/index.ts

@@ -19,6 +19,7 @@ import { renderEmergency } from './dialplan/emergency.ts';
 import { renderRingGroups } from './dialplan/ringgroups.ts';
 import { renderIvrs } from './dialplan/ivrs.ts';
 import { renderTimeConditions } from './dialplan/timeconditions.ts';
+import { renderAnnouncements } from './dialplan/announcements.ts';
 import { renderVoicemail } from './voicemail.ts';
 
 export { renderTransports };
@@ -54,6 +55,7 @@ const BODIES: Partial<Record<GeneratedFileName, (snap: Snapshot) => string>> = {
       renderRingGroups(snap),
       renderIvrs(snap),
       renderTimeConditions(snap),
+      renderAnnouncements(snap),
       renderTrunkEntries(snap),
       renderDids(snap),
       renderOutbound(snap),