moh: music-on-hold classes, uploads, pickers for users and queues

/api/moh-classes: create (slug, not "default"), delete (409 while an
extension or queue uses it), add/play/remove files. Files are 8 kHz
wav in MOH_DIR/<class>/ and sound_files rows of kind moh. Extensions
and queues may only pick default or an existing class.

Two things found with real calls, written back into 03 and 04:
- An empty class plays silence on Asterisk 24. Only classes with
  music are rendered, so a channel asking for an empty one gets
  default.
- The generator reloads only changed files, and a file upload changes
  no config (except a class's first/last). The route sends moh reload
  after every file change.

Web: a Music on hold section on Sounds & music, and a select of sets
in the user drawer's Phone tab and the queue form. load-golden makes
the class folders like the api does. Golden case queue gains two
classes. e2e m8-t5: set made in the UI, upload listed by Asterisk, a
queue caller hears it, a user's moh_suggest, delete refused while
used, an emptied set falls back to default.

Task: M8-T5

apps/api/test/asterisk/load-golden.mjs

@@ -4,7 +4,15 @@
 // Needs Docker and a built image (ASTERISK_IMAGE, default "selfphoneng-asterisk").
 // Usage: pnpm test:asterisk [case ...]
 import { spawnSync } from 'node:child_process';
-import { cpSync, existsSync, mkdtempSync, readdirSync, readFileSync, rmSync } from 'node:fs';
+import {
+  cpSync,
+  existsSync,
+  mkdirSync,
+  mkdtempSync,
+  readdirSync,
+  readFileSync,
+  rmSync,
+} from 'node:fs';
 import { tmpdir } from 'node:os';
 import { join } from 'node:path';
 import { fileURLToPath } from 'node:url';
@@ -40,6 +48,11 @@ async function check(name) {
   const tmp = mkdtempSync(join(tmpdir(), `sp-golden-${name}-`));
   cpSync(join(GOLDEN, name, 'expected'), tmp, { recursive: true });
   const problems = [];
+  // The api makes each MOH class's folder when the class is created (routes/moh.ts); do the same.
+  const moh = mkdtempSync(join(tmpdir(), `sp-golden-moh-`));
+  const mohConf = readFileSync(join(tmp, 'musiconhold_selfphoneng.conf'), 'utf8');
+  for (const [, d] of mohConf.matchAll(/^directory = \/var\/lib\/asterisk\/moh\/(.+)$/gm))
+    mkdirSync(join(moh, d));
   const run = docker(
     'run',
     '-d',
@@ -50,6 +63,8 @@ async function check(name) {
     'AMI_SECRET=golden-test-secret',
     '-v',
     `${tmp}:/etc/asterisk/selfphoneng`,
+    '-v',
+    `${moh}:/var/lib/asterisk/moh`,
     IMAGE,
   );
   if (!run.ok) throw new Error(`docker run failed: ${run.out}`);
@@ -90,6 +105,7 @@ async function check(name) {
   } finally {
     docker('rm', '-f', NAME);
     rmSync(tmp, { recursive: true, force: true });
+    rmSync(moh, { recursive: true, force: true });
   }
 }