feat: M2 database migration runner with Phinx and initial schema

phinx.php

@@ -0,0 +1,41 @@
+<?php
+
+declare(strict_types=1);
+
+use Phinx\Config\Config;
+
+/**
+ * Phinx configuration for MeshVault database migrations.
+ *
+ * Uses environment variables from the application configuration (AppConfig)
+ * for database connection. Migrations are stored in db/migrations/.
+ */
+
+// Load environment from getenv() - Compose injects these into the container
+$dbHost = getenv('MESHVAULT_DB_HOST') ?: 'db';
+$dbPort = (int) (getenv('MESHVAULT_DB_PORT') ?: 5432);
+$dbName = getenv('MESHVAULT_DB_NAME') ?: 'meshvault';
+$dbUser = getenv('MESHVAULT_DB_USER') ?: 'meshvault';
+$dbPass = getenv('MESHVAULT_DB_PASSWORD') ?: '';
+
+return [
+    'paths' => [
+        'migrations' => 'db/migrations',
+        'seeds' => 'db/seeds',
+    ],
+    'environments' => [
+        'default_migration_table' => 'phinxlog',
+        'default_database' => 'development',
+        'development' => [
+            'adapter' => 'pgsql',
+            'host' => $dbHost,
+            'port' => $dbPort,
+            'name' => $dbName,
+            'user' => $dbUser,
+            'pass' => $dbPass,
+            'charset' => 'utf8',
+        ],
+    ],
+    'version_order' => 'creation',
+    'migration_base_class' => 'Phinx\Migration\AbstractMigration',
+];