feat(backup): full DR bundle export + admin-configurable offsite destinations

Backend-agnostic disaster-recovery backup engine that runs on the current
storage backend (no storage cutover required):

- Full-bundle export: db.dump (pg_dump custom) + every storage blob +
  manifest.json with per-object SHA-256, streamed as a tar. Entry points:
  admin UI download, GET /api/v1/admin/backup/export, scripts/create-full-backup.ts.
- Admin-configurable push destinations (backup_destinations table, migration
  0091): SFTP/SSH, S3-compatible (reuses the minio client), and mounted
  path/NAS behind one transport interface (test/push/prune). Secrets AES-GCM
  at rest; API returns only *IsSet markers.
- Opt-in per-destination AES-256 bundle encryption (scrypt KDF, streamed) +
  scripts/decrypt-backup.ts for restore.
- Wired the previously-dead database-backup cron to runScheduledBackupPush
  (push to enabled destinations, prune to retention, alert super-admins on
  failure).

Tests: 1608 unit/integration pass; tsc + lint clean.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

tests/unit/services/backup-transport-factory.test.ts

@@ -0,0 +1,63 @@
+/**
+ * Unit test for the transport factory + S3 endpoint parser
+ * (`src/lib/services/backup-destinations/`).
+ */
+
+import { describe, expect, it } from 'vitest';
+
+import {
+  buildTransport,
+  FilesystemTransport,
+  parseS3Endpoint,
+  S3Transport,
+  SftpTransport,
+} from '@/lib/services/backup-destinations';
+
+describe('buildTransport', () => {
+  it('builds the right transport per type', () => {
+    expect(buildTransport('filesystem', { directory: '/x' })).toBeInstanceOf(FilesystemTransport);
+    expect(buildTransport('sftp', { host: 'h', username: 'u', remoteDir: '/d' })).toBeInstanceOf(
+      SftpTransport,
+    );
+    expect(
+      buildTransport('s3', { endpoint: 'h', bucket: 'b', accessKey: 'a', secretKey: 's' }),
+    ).toBeInstanceOf(S3Transport);
+  });
+
+  it('throws on an unknown type', () => {
+    // @ts-expect-error testing the runtime guard
+    expect(() => buildTransport('ftp', {})).toThrow(/Unknown backup destination type/);
+  });
+});
+
+describe('parseS3Endpoint', () => {
+  it('parses an https URL into host + ssl', () => {
+    expect(parseS3Endpoint('https://s3.eu-central.example.com', {})).toEqual({
+      endPoint: 's3.eu-central.example.com',
+      useSSL: true,
+    });
+  });
+
+  it('parses an http URL with a port', () => {
+    expect(parseS3Endpoint('http://localhost:9000', {})).toEqual({
+      endPoint: 'localhost',
+      port: 9000,
+      useSSL: false,
+    });
+  });
+
+  it('treats a bare host as ssl-by-default', () => {
+    expect(parseS3Endpoint('s3.amazonaws.com', {})).toEqual({
+      endPoint: 's3.amazonaws.com',
+      useSSL: true,
+    });
+  });
+
+  it('honours explicit useSSL=false on a bare host', () => {
+    expect(parseS3Endpoint('minio.internal', { useSSL: false, port: 9000 })).toEqual({
+      endPoint: 'minio.internal',
+      port: 9000,
+      useSSL: false,
+    });
+  });
+});