Send signed outgoing webhooks

Fed by the records themselves, delivered only to public HTTPS addresses
checked at every attempt, retried, and switched off after repeated failures.
A submitter's details travel only to webhooks that opted into them.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

app/Models/Webhook.php

@@ -0,0 +1,80 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Models;
+
+use Illuminate\Database\Eloquent\Attributes\Fillable;
+use Illuminate\Database\Eloquent\Attributes\Hidden;
+use Illuminate\Database\Eloquent\Builder;
+use Illuminate\Database\Eloquent\Factories\HasFactory;
+use Illuminate\Database\Eloquent\Model;
+use Illuminate\Database\Eloquent\Relations\HasMany;
+
+/**
+ * Somewhere to tell when something happens here.
+ */
+#[Fillable(['name', 'url', 'secret', 'events', 'include_personal_data', 'is_active'])]
+#[Hidden(['secret'])]
+class Webhook extends Model
+{
+    use HasFactory;
+
+    /**
+     * What can be subscribed to. `*` is all of them.
+     */
+    public const EVENTS = [
+        'application.received',
+        'content.published',
+        'content.unpublished',
+        'review.requested',
+        'review.returned',
+    ];
+
+    /**
+     * Switched off after this many failed deliveries in a row, so a dead
+     * endpoint does not keep a queue busy forever. Switching it back on is a
+     * person's decision.
+     */
+    public const MAX_FAILURES = 20;
+
+    protected $attributes = [
+        'include_personal_data' => false,
+        'is_active' => true,
+    ];
+
+    protected function casts(): array
+    {
+        return [
+            'secret' => 'encrypted',
+            'events' => 'array',
+            'include_personal_data' => 'boolean',
+            'is_active' => 'boolean',
+            'last_delivered_at' => 'datetime',
+        ];
+    }
+
+    /**
+     * @return HasMany<WebhookDelivery, $this>
+     */
+    public function deliveries(): HasMany
+    {
+        return $this->hasMany(WebhookDelivery::class)->latest('id');
+    }
+
+    public function listensTo(string $event): bool
+    {
+        $events = $this->events ?? [];
+
+        return in_array('*', $events, true) || in_array($event, $events, true);
+    }
+
+    /**
+     * @param  Builder<$this>  $query
+     * @return Builder<$this>
+     */
+    public function scopeActive(Builder $query): Builder
+    {
+        return $query->where('is_active', true);
+    }
+}