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/golden-case.ts

@@ -17,6 +17,7 @@ export function loadCase(name: string): Snapshot {
     dids?: Partial<Snapshot['dids'][number]>[];
     trunks?: Partial<Snapshot['trunks'][number]>[];
     routes?: Partial<Snapshot['routes'][number]>[];
+    ringGroups?: Partial<Snapshot['ringGroups'][number]>[];
   };
   const settings = Object.fromEntries(
     (Object.keys(SettingsSchemas) as SettingKey[])
@@ -35,6 +36,18 @@ export function loadCase(name: string): Snapshot {
       id: d.id!,
       number: d.number!,
     })),
+    ringGroups: (raw.ringGroups ?? []).map((g, i) => ({
+      name: `Group ${i + 1}`,
+      strategy: 'ringall',
+      ringSeconds: 25,
+      callerIdNamePrefix: null,
+      musicInsteadOfRing: false,
+      members: [],
+      noAnswerDestination: { type: 'hangup' as const },
+      ...g,
+      id: g.id!,
+      number: g.number!,
+    })),
     routes: (raw.routes ?? []).map((r, i) => ({
       name: `Route ${i + 1}`,
       position: i,