Adds minimal app services API for plugins

app/core/App.php

@@ -0,0 +1,96 @@
+<?php
+
+namespace App;
+
+/**
+ * Minimal application API
+ * we use it expose and access core services from plugins (and legacy code).
+ */
+final class App
+{
+    /** @var array<string, mixed> */
+    private static array $services = [];
+
+    /**
+     * Register or override a service value.
+     */
+    public static function set(string $key, $value): void
+    {
+        self::$services[$key] = $value;
+    }
+
+    /**
+     * Determine whether a value is registered.
+     */
+    public static function has(string $key): bool
+    {
+        if (array_key_exists($key, self::$services)) {
+            return true;
+        }
+        return self::fallback($key) !== null;
+    }
+
+    /**
+     * Retrieve a registered value.
+     * Falls back to legacy globals when no explicit service was registered.
+     */
+    public static function get(string $key, $default = null)
+    {
+        if (array_key_exists($key, self::$services)) {
+            return self::$services[$key];
+        }
+        $fallback = self::fallback($key);
+        return $fallback !== null ? $fallback : $default;
+    }
+
+    /**
+     * Convenience accessor for the database connection.
+     */
+    public static function db()
+    {
+        return self::get('db');
+    }
+
+    /**
+     * Convenience accessor for the configuration array.
+     */
+    public static function config(): array
+    {
+        $config = self::get('config', []);
+        return is_array($config) ? $config : [];
+    }
+
+    /**
+     * Convenience accessor for the authenticated user object, if any.
+     */
+    public static function user()
+    {
+        return self::get('user');
+    }
+
+    /**
+     * Basic fallback bridge for legacy globals.
+     */
+    private static function fallback(string $key)
+    {
+        switch ($key) {
+            case 'config':
+                return $GLOBALS['config'] ?? null;
+            case 'config_path':
+                return $GLOBALS['config_file'] ?? null;
+            case 'db':
+                return $GLOBALS['db'] ?? null;
+            case 'user':
+            case 'user_object':
+                return $GLOBALS['userObject'] ?? null;
+            case 'user_id':
+                return $GLOBALS['userId'] ?? null;
+            case 'logger':
+                return $GLOBALS['logObject'] ?? null;
+            case 'app_root':
+                return $GLOBALS['app_root'] ?? null;
+            default:
+                return null;
+        }
+    }
+}