update: the api backs up before migrating; scripts/update.sh for compose installs

Docker only, never bare metal (owner, 2026-10-21). A new version with pending migrations backs
up first (database, voicemail, sounds, MOH) and stops if it can't (SKIP_BACKUP_BEFORE_MIGRATE
to override). update.sh: checks, changelog, backup (node dist/backup-cli.js), log compaction,
build while the old version runs, restart, self-check, and rollback with restore. Container
logs capped in compose. Admin guide: Updating, for compose and Portainer.

apps/api/src/db/client.ts

@@ -1,5 +1,8 @@
 // SPDX-License-Identifier: AGPL-3.0-or-later
+import { readFile } from 'node:fs/promises';
+import { join } from 'node:path';
 import { fileURLToPath } from 'node:url';
+import { sql } from 'drizzle-orm';
 import { drizzle } from 'drizzle-orm/node-postgres';
 import { migrate } from 'drizzle-orm/node-postgres/migrator';
 import pg from 'pg';
@@ -19,3 +22,21 @@ export type Db = ReturnType<typeof createDb>['db'];
 export async function runMigrations(db: Db): Promise<void> {
   await migrate(db, { migrationsFolder: MIGRATIONS_DIR });
 }
+
+/**
+ * This image has migrations the database hasn't run yet. False for an empty database (a fresh
+ * install: nothing to lose). Reads drizzle's own bookkeeping, `drizzle.__drizzle_migrations`.
+ */
+export async function migrationsPending(db: Db, folder = MIGRATIONS_DIR): Promise<boolean> {
+  const journal = JSON.parse(await readFile(join(folder, 'meta', '_journal.json'), 'utf8')) as {
+    entries: unknown[];
+  };
+  const t = await db.execute<{ t: string | null }>(
+    sql`select to_regclass('drizzle.__drizzle_migrations')::text as t`,
+  );
+  if (!t.rows[0]?.t) return false;
+  const r = await db.execute<{ n: number }>(
+    sql`select count(*)::int as n from drizzle.__drizzle_migrations`,
+  );
+  return r.rows[0]!.n < journal.entries.length;
+}