feat: M2 database migration runner with Phinx and initial schema

phpcs.xml.dist

@@ -10,5 +10,12 @@
     <file>bin</file>
     <file>templates</file>
     <file>db/migrations</file>
+    <file>db/seeds</file>
     <file>tests</file>
+    <!-- Phinx migration/seed classes are global by framework convention. -->
+    <rule ref="PSR1.Classes.ClassDeclaration.MissingNamespace">
+        <include-pattern>db/migrations/*</include-pattern>
+        <include-pattern>db/seeds/*</include-pattern>
+        <severity>0</severity>
+    </rule>
 </ruleset>