Scaffold Symfony 8 app with Bootstrap/DataTables and Docker stack

- Symfony 8.1 webapp skeleton on PHP 8.5 (AssetMapper/importmap, no Node)
- Form-login gate: User entity, security.yaml, SecurityController,
  app:user:create command, initial migration (user + messenger_messages)
- Bootstrap 5 + DataTables layout (base/login/home templates); any
  table.datatable is auto-initialised
- trusted_proxies/headers wired for the shared Nginx Proxy Manager
- Docker (servers only): docker-compose.yml (php:8.5-fpm-alpine,
  nginx:1.30-alpine, mariadb:12.3; host ports 8085/3310; external
  docker_default network) + docker/{Dockerfile,php.ini,nginx,setup.sh,restart.sh}
- .env with CHANGEME placeholders (no secrets), .gitattributes enforces
  LF so the deploy scripts stay runnable on Linux

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

importmap.php

@@ -0,0 +1,36 @@
+<?php
+
+/**
+ * Returns the importmap for this application.
+ *
+ * - "path" is a path inside the asset mapper system. Use the
+ *     "debug:asset-map" command to see the full list of paths.
+ *
+ * - "entrypoint" (JavaScript only) set to true for any module that will
+ *     be used as an "entrypoint" (and passed to the importmap() Twig function).
+ *
+ * The "importmap:require" command can be used to add new entries to this file.
+ *
+ * @return array<string, array{    // Import name as key, description of the imported file as value
+ *     path: string,               // Logical, relative or absolute path to the file
+ *     type?: 'js'|'css'|'json',   // Type of the file, defaults to 'js'
+ *     entrypoint?: bool,          // Whether the file is an entrypoint, for 'js' only
+ * }|array{
+ *     version: string,            // Version of the remote package
+ *     package_specifier?: string, // Remote "package-name/path" specifier, defaults to the import name
+ *     type?: 'js'|'css'|'json',
+ *     entrypoint?: bool,
+ * }>
+ */
+return [
+    'app' => ['path' => './assets/app.js', 'entrypoint' => true],
+    '@hotwired/stimulus' => ['version' => '3.2.2'],
+    '@symfony/stimulus-bundle' => ['path' => './vendor/symfony/stimulus-bundle/assets/dist/loader.js'],
+    '@hotwired/turbo' => ['version' => '8.0.23'],
+    'bootstrap' => ['version' => '5.3.8'],
+    '@popperjs/core' => ['version' => '2.11.8'],
+    'datatables.net-bs5' => ['version' => '3.0.3'],
+    'datatables.net' => ['version' => '3.0.3'],
+    'bootstrap/dist/css/bootstrap.min.css' => ['version' => '5.3.8', 'type' => 'css'],
+    'datatables.net-bs5/css/dataTables.bootstrap5.min.css' => ['version' => '3.0.3', 'type' => 'css'],
+];