music on hold: play order set in the UI, and shuffle

Owner: the first upload always played first. A class is now an Asterisk playlist in the order
set on Sounds & music (move up/down), new uploads last, with a Shuffle option (sort = random).
moh-test.ts plays both in a real Asterisk and reads the file order from its debug log.

apps/api/src/db/migrations/0005_moh_order.sql

@@ -0,0 +1,7 @@
+ALTER TABLE "moh_classes" ADD COLUMN "shuffle" boolean DEFAULT false NOT NULL;--> statement-breakpoint
+ALTER TABLE "sound_files" ADD COLUMN "position" integer DEFAULT 0 NOT NULL;--> statement-breakpoint
+-- Existing music on hold keeps the order it was uploaded in (owner, 2026-10-21).
+UPDATE "sound_files" s SET "position" = o.n FROM (
+  SELECT "id", row_number() OVER (PARTITION BY "moh_class_id" ORDER BY "created_at", "id") - 1 AS n
+  FROM "sound_files" WHERE "moh_class_id" IS NOT NULL
+) o WHERE s."id" = o."id";

apps/api/src/db/migrations/meta/_journal.json

@@ -36,6 +36,13 @@
       "when": 1792512298128,
       "tag": "0004_system_events",
       "breakpoints": true
+    },
+    {
+      "idx": 5,
+      "version": "7",
+      "when": 1792606712441,
+      "tag": "0005_moh_order",
+      "breakpoints": true
     }
   ]
 }

apps/api/src/db/schema.ts

@@ -334,6 +334,8 @@ export const queueCalls = pgTable(
 export const mohClasses = pgTable('moh_classes', {
   id: id(),
   name: text().notNull().unique(),
+  /** Play the files in random order; otherwise in `sound_files.position` order (03 §8). */
+  shuffle: boolean().notNull().default(false),
   ...timestamps,
 });
 
@@ -349,6 +351,8 @@ export const soundFiles = pgTable(
     originalFilename: text(),
     asteriskName: text().notNull().unique(),
     durationMs: integer().notNull(),
+    /** Music on hold: where it plays in its class's list (0 first). Prompts don't use it. */
+    position: integer().notNull().default(0),
     ...timestamps,
   },
   (t) => [