feat(app): Added CI_App application driver spine

Introduce a bare-bones `CI_App` driver library as the application-level entry point, parallel to `CI_Hub` but scoped to domain logic.

Includes an empty drivers directory to establish the extension surface. `CI_App` is shipped inactive by default and intended to be autoloaded only when an application requires app-side hooks or drivers.

Author: bkader

application/bootstrap.php

@@ -8,7 +8,7 @@
 | Used to track app status and possibly check for updates.
 |
 */
-const APP_VERSION = '0.1.1';
+const APP_VERSION = '0.1.2';
 const APP_REPO = 'ianhubnet/csk-app-default';
 
 /*

application/config/constants.php

@@ -1,7 +1,5 @@
 <?php
 
-defined('BASEPATH') || exit('A moment of silence for your attempt.');
-
 /**
  * Application Constants
  *

application/libraries/App/App.php

@@ -0,0 +1,98 @@
+<?php
+
+/**
+ * CI_App
+ *
+ * Application-level driver library.
+ *
+ * Acts as the main entry point for application-specific logic and domain
+ * drivers, fully isolated from the framework/core layer (CI_Hub).
+ *
+ * This class is intentionally lightweight by default and may remain unused
+ * unless explicitly autoloaded by the application..
+ *
+ * @package     App\Libraries
+ * @subpackage  Drivers
+ * @author      Kader Bouyakoub <bkader[at]mail[dot]com>
+ * @copyright   Copyright (c) 2025, Kader Bouyakoub
+ */
+
+final class CI_App extends CI_Driver_Library
+{
+	/**
+	 * Reference to the CodeIgniter super-object.
+	 *
+	 * Used to access loaders, hooks, config, and other shared services.
+	 *
+	 * @var CI_Controller
+	 */
+	protected $ci;
+
+	/**
+	 * List of allowed application drivers.
+	 *
+	 * This list is filterable to allow applications or modules to register
+	 * their own drivers without modifying this class.
+	 *
+	 * @var array<string>
+	 */
+	protected $valid_drivers;
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Class constructor.
+	 *
+	 * Initializes the application driver library and prepares the list
+	 * of valid drivers. Logic here is not executed unless the library is
+	 * explicitly (auto)loaded.
+	 *
+	 * @return void
+	 */
+	public function __construct()
+	{
+		// Cache the CI super-object for convenience and performance.
+		$this->ci ??= CI_Controller::get_instance();
+
+		/**
+		 * Filter the list of application drivers.
+		 *
+		 * Applications are expected to register their drivers through
+		 * the `app_drivers` filter when needed. However, default drivers
+		 * can be added here and the filter is left to modules and plugins.
+		 */
+		$this->valid_drivers = $this->ci->hooks->filter(
+			'app_drivers',
+			[], // Add default drivers here.
+			$this->ci,
+			$this
+		);
+
+		// Skip runtime setup during installation.
+		if (CI_INSTALL) {
+			return;
+		}
+
+		// Allow the application to hook into runtime execution.
+		$this->setup_runtime();
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Performs optional runtime setup.
+	 *
+	 * Intended for registering hooks, menus, listeners, or other
+	 * application-specific behavior.
+	 *
+	 * This method is intentionally empty in the default distribution
+	 * and should only be implemented when the application requires it.
+	 *
+	 * @return void
+	 */
+	private function setup_runtime()
+	{
+		// Intentionally left blank.
+	}
+
+}