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/Delivery/DeliverJob.php

@@ -0,0 +1,58 @@
+<?php
+
+namespace App\Delivery;
+
+use App\Channels\ChannelRegistry;
+use App\Enums\DeliveryResult;
+use App\Models\Delivery;
+use Illuminate\Contracts\Queue\ShouldQueue;
+use Illuminate\Foundation\Queue\Queueable;
+use Throwable;
+
+final class DeliverJob implements ShouldQueue
+{
+    use Queueable;
+
+    public int $tries = 3;
+
+    public function __construct(public readonly int $deliveryId) {}
+
+    /** @return list<int> */
+    public function backoff(): array
+    {
+        return [30, 120, 600];
+    }
+
+    public function handle(ChannelRegistry $registry): void
+    {
+        $delivery = Delivery::with(['event.user', 'event.source', 'channel'])->findOrFail($this->deliveryId);
+        if ($delivery->result !== DeliveryResult::Pending) {
+            return;
+        }
+
+        if ($delivery->event->isTerminal()) {
+            $delivery->update(['result' => DeliveryResult::Failed, 'error' => 'skipped: событие уже закрыто']);
+
+            return;
+        }
+
+        $outcome = $registry->for($delivery->channel->type)
+            ->deliver($delivery->event, $delivery->event->user, $delivery->channel->config, $delivery);
+
+        if ($outcome->ok) {
+            $delivery->update(['result' => DeliveryResult::Ok, 'sent_at' => now(), 'error' => null, 'meta' => $outcome->meta]);
+
+            return;
+        }
+
+        $delivery->update(['error' => $outcome->error]);
+        throw new DeliveryFailed($outcome->error ?? 'delivery failed');
+    }
+
+    public function failed(Throwable $e): void
+    {
+        Delivery::whereKey($this->deliveryId)
+            ->where('result', DeliveryResult::Pending->value)
+            ->update(['result' => DeliveryResult::Failed, 'error' => $e->getMessage()]);
+    }
+}