feat: tick planner, delivery job, scheduler and purge

Also: test uses disabled channels instead of deleting them (FK cascade); ChannelRegistry no longer final so tests can extend it (controller ruling).

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01BCrwHHnGCB5XH968Nxokqw

core/app/Providers/AppServiceProvider.php

@@ -22,6 +22,15 @@ class AppServiceProvider extends ServiceProvider
             config('hado.telegram.token'),
             config('hado.telegram.seen_ttl'),
         ));
+
+        $this->app->bind(\App\Delivery\Tick::class, fn ($app) => new \App\Delivery\Tick(
+            $app->make(\App\Scheduling\DueResolver::class),
+            $app->make(\App\Scheduling\StateResolver::class),
+            $app->make(\App\Scheduling\WindowResolver::class),
+            $app->make(\App\Channels\ChannelRegistry::class),
+            $app->make('cache.store'),
+            config('hado.presence_ttl'),
+        ));
     }
 
     /**