chore: setup PHP_CodeSniffer for project tooling

.phive/phars.xml

@@ -2,4 +2,6 @@
 <phive xmlns="https://phar.io/phive">
   <phar name="phpstan" version="1.10.60" installed="1.10.60" location="./tools/phpstan" copy="false"/>
   <phar name="phpunit" version="^10.5.16" installed="10.5.16" location="./tools/phpunit" copy="false"/>
+  <phar name="phpcs" version="^3.10.2" installed="3.10.2" location="./tools/phpcs" copy="false"/>
+  <phar name="phpcbf" version="^3.10.2" installed="3.10.2" location="./tools/phpcbf" copy="false"/>
 </phive>

phpcs.xml.dist

+<?xml version="1.0"?>
+<ruleset>
+    <!-- Use PSR-12 ruleset -->
+    <rule ref="PSR12"/>
+
+    <!-- Only scan *.php files -->
+    <arg name="extensions" value="php"/>
+
+    <!-- Ignore warnings -->
+    <arg name="warning-severity" value="0"/>
+
+    <!-- Process 64 (or number of CPU cores) files in parallel -->
+    <arg name="parallel" value="64"/>
+
+    <!-- Output relative file paths, by setting the current folder as the basepath -->
+    <arg name="basepath" value="."/>
+
+    <!-- Show colored output -->
+    <arg name="colors"/>
+
+    <!-- Scan everything in the current folder -->
+    <file>.</file>
+</ruleset>