ringgroups: ring-all and hunt groups, API, page, golden case

/api/ring-groups CRUD with members as ordered memberIds (unique, must
exist), number from the ring-group range, a no-answer destination
(never itself), and delete refused while something points at it. The
generator renders sp-rg-{id} (Dial through sp-rg-member: all at once with
the total ring time, or one at a time with the per-member time, music
instead of ringing on request), adds the number to sp-local-numbers, and
destApp sends ring_group destinations there. Golden case ringgroups.

The DestinationPicker is now generic over targets picked by id and gains
"Voicemail of a user" and "Ring group" (M6-T6 completes it). Caller-name
prefixes (DIDs and ring groups) get a space before the caller's name.
Ring groups page with an ordered member list.

e2e m6-t2 found the new-group form failing on an unset no-answer
destination (fixed: defaults to hang up). It checks ring-all (both ring,
191 answers) and hunt (190 alone for 5 s, then 191) with real calls. The
generator debounce test now waits for the apply instead of a fixed 150 ms.

Task: M6-T2

apps/api/src/generator/index.ts

@@ -16,6 +16,7 @@ import { renderGlobals, renderLocalNumbers } from './dialplan/local.ts';
 import { renderDids, renderTrunkEntries } from './dialplan/inbound.ts';
 import { renderOutbound } from './dialplan/outbound.ts';
 import { renderEmergency } from './dialplan/emergency.ts';
+import { renderRingGroups } from './dialplan/ringgroups.ts';
 import { renderVoicemail } from './voicemail.ts';
 
 export { renderTransports };
@@ -48,6 +49,7 @@ const BODIES: Partial<Record<GeneratedFileName, (snap: Snapshot) => string>> = {
     [
       STATIC_DIALPLAN,
       renderLocalNumbers(snap),
+      renderRingGroups(snap),
       renderTrunkEntries(snap),
       renderDids(snap),
       renderOutbound(snap),