chore: bootstrap PHP quality toolchain

.gitignore

@@ -1 +1,3 @@
 .worktrees/
+/vendor/
+/var/

composer.json

@@ -0,0 +1,40 @@
+{
+    "name": "battleforge/battleforge",
+    "description": "A standalone tactical combat game.",
+    "license": "proprietary",
+    "require": {
+        "php": "^8.3"
+    },
+    "require-dev": {
+        "dealerdirect/phpcodesniffer-composer-installer": "^1.0",
+        "phpstan/phpstan": "^2.0",
+        "phpunit/phpunit": "^11.5",
+        "squizlabs/php_codesniffer": "^3.10"
+    },
+    "autoload": {
+        "psr-4": {
+            "BattleForge\\": "src/"
+        }
+    },
+    "autoload-dev": {
+        "psr-4": {
+            "BattleForge\\Tests\\": "tests/"
+        }
+    },
+    "scripts": {
+        "lint": "phpcs",
+        "analyse": "phpstan analyse --no-progress",
+        "test": "phpunit",
+        "check": [
+            "@lint",
+            "@analyse",
+            "@test"
+        ]
+    },
+    "config": {
+        "allow-plugins": {
+            "dealerdirect/phpcodesniffer-composer-installer": true
+        },
+        "sort-packages": true
+    }
+}

phpcs.xml

@@ -0,0 +1,12 @@
+<?xml version="1.0"?>
+<ruleset name="BattleForge">
+    <description>BattleForge coding standards.</description>
+
+    <file>src</file>
+    <file>tests</file>
+
+    <arg name="colors"/>
+    <arg value="sp"/>
+
+    <rule ref="PSR12"/>
+</ruleset>

phpstan.neon

@@ -0,0 +1,6 @@
+parameters:
+    level: 6
+    paths:
+        - src
+        - tests
+    tmpDir: var/phpstan

phpunit.xml

@@ -0,0 +1,18 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/11.5/phpunit.xsd"
+         bootstrap="vendor/autoload.php"
+         cacheDirectory="var/phpunit"
+         colors="true">
+    <testsuites>
+        <testsuite name="BattleForge Test Suite">
+            <directory>tests</directory>
+        </testsuite>
+    </testsuites>
+
+    <source>
+        <include>
+            <directory>src</directory>
+        </include>
+    </source>
+</phpunit>