ivrs: digital receptionist with keypad grid, SoundPicker, golden case

/api/ivrs CRUD: greeting and wrong-key sounds must be prompts, every
option destination must exist (an option may point at its own menu),
keys unique; delete drops the menu's own options before checking
references, inside a transaction so a refused delete keeps them. The
generator renders sp-ivr-{id} per 03 §6.9 (Background greeting,
WaitExten, keys sorted, i/t retry then give up, include sp-local-numbers
for direct dial), adds the number to sp-local-numbers, and destApp sends
ivr destinations there. Golden case ivr (incl. # and self-reference).

Web: Digital receptionist page with a 3x4 keypad grid (pick a key, then
its destination or "unused"), SoundPicker (pick, play, upload new right
in the form), DestinationPicker gains "Digital receptionist" and a shared
target source; useDescribeDestination labels unsaved keys.

e2e m6-t3: menu built in the UI, the greeting plays, keys 1/2 ring the
right phones, a wrong key plays pbx-invalid and repeats the greeting.

Task: M6-T3

apps/api/src/generator/golden-case.ts

@@ -18,6 +18,7 @@ export function loadCase(name: string): Snapshot {
     trunks?: Partial<Snapshot['trunks'][number]>[];
     routes?: Partial<Snapshot['routes'][number]>[];
     ringGroups?: Partial<Snapshot['ringGroups'][number]>[];
+    ivrs?: Partial<Snapshot['ivrs'][number]>[];
   };
   const settings = Object.fromEntries(
     (Object.keys(SettingsSchemas) as SettingKey[])
@@ -36,6 +37,20 @@ export function loadCase(name: string): Snapshot {
       id: d.id!,
       number: d.number!,
     })),
+    ivrs: (raw.ivrs ?? []).map((r, i) => ({
+      name: `Menu ${i + 1}`,
+      greeting: 'custom/greeting',
+      invalidSound: null,
+      timeoutSeconds: 5,
+      maxRetries: 3,
+      allowDirectDial: true,
+      options: [],
+      timeoutDestination: { type: 'hangup' as const },
+      invalidDestination: { type: 'hangup' as const },
+      ...r,
+      id: r.id!,
+      number: r.number!,
+    })),
     ringGroups: (raw.ringGroups ?? []).map((g, i) => ({
       name: `Group ${i + 1}`,
       strategy: 'ringall',