[1.x] Fix abandoned-extensions sync never being scheduled

The sync command was registered onto `flarum.console.scheduled` in
ExtensionServiceProvider::boot(). ConsoleServiceProvider consumes that array
in its own boot() and is registered first, so the entry was appended too
late and the task was never scheduled. Move the command and schedule
registration into register() so it is present when the schedule is built.

Fixes #4705

Author: imorland

framework/core/src/Extension/ExtensionServiceProvider.php

@@ -45,18 +45,12 @@ public function register()
         $this->container['flarum']->booting(function () {
             $this->container->make('flarum.extensions')->extend($this->container);
         });
-    }
-
-    /**
-     * {@inheritdoc}
-     */
-    public function boot(Dispatcher $events)
-    {
-        $events->listen(
-            Disabling::class,
-            DefaultLanguagePackGuard::class
-        );
 
+        // Register the abandoned-extensions sync command and its weekly schedule here in
+        // register() rather than boot(). The ConsoleServiceProvider consumes the
+        // `flarum.console.scheduled` array in its own boot() method, and it is registered
+        // before this provider, so appending in boot() would happen too late and the task
+        // would never be scheduled.
         $this->container->extend('flarum.console.commands', function (array $commands) {
             $commands[] = SyncAbandonedExtensionsCommand::class;
 
@@ -73,4 +67,15 @@ public function boot(Dispatcher $events)
             return $scheduled;
         });
     }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function boot(Dispatcher $events)
+    {
+        $events->listen(
+            Disabling::class,
+            DefaultLanguagePackGuard::class
+        );
+    }
 }

framework/core/tests/integration/extension/ScheduledAbandonedSyncTest.php

@@ -0,0 +1,34 @@
+<?php
+
+/*
+ * This file is part of Flarum.
+ *
+ * For detailed copyright and license information, please view the
+ * LICENSE file that was distributed with this source code.
+ */
+
+namespace Flarum\Tests\integration\extension;
+
+use Flarum\Testing\integration\ConsoleTestCase;
+
+class ScheduledAbandonedSyncTest extends ConsoleTestCase
+{
+    /**
+     * The abandoned-extensions sync command is registered by core's ExtensionServiceProvider.
+     * It must end up in the scheduler so the abandoned list is refreshed automatically.
+     *
+     * This is a regression test: the registration was previously done in the provider's boot()
+     * method, which ran after ConsoleServiceProvider::boot() had already consumed the
+     * `flarum.console.scheduled` array, so the task was silently dropped and never scheduled.
+     *
+     * @test
+     */
+    public function abandoned_sync_command_is_scheduled()
+    {
+        $output = $this->runCommand([
+            'command' => 'schedule:list',
+        ]);
+
+        $this->assertStringContainsString('extensions:sync-abandoned', $output);
+    }
+}