Add missing app files and fix Docker configuration

- Add all PHP app files (controllers, middleware, providers, models, enums)
  that were previously gitignored via app/.gitignore wildcard
- Fix app/.gitignore to no longer ignore all files
- Fix docker-compose.yml: use named volume for postgres to avoid chown permission errors on server
- Fix Dockerfile: use --classmap-authoritative for composer dump-autoload

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

app/Enums/RoleEnum.php

@@ -0,0 +1,11 @@
+<?php
+
+namespace App\Enums;
+
+enum RoleEnum: string
+{
+    case ADMIN = 'admin';
+    case USER = 'user';
+    case APPRAISER = 'appraiser';
+    case DILLER = 'diller';
+}