Send Brrr push notifications for new webmentions

Dispatches a queued job to POST to a configured Brrr webhook whenever
a brand-new webmention is saved, so replies/likes/reposts show up as
push notifications instead of requiring a manual check of the site.

app/Jobs/NotifyBrrrOfWebMention.php

@@ -0,0 +1,56 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Jobs;
+
+use App\Models\WebMention;
+use Illuminate\Bus\Queueable;
+use Illuminate\Contracts\Queue\ShouldQueue;
+use Illuminate\Foundation\Bus\Dispatchable;
+use Illuminate\Queue\InteractsWithQueue;
+use Illuminate\Queue\SerializesModels;
+use Illuminate\Support\Facades\Http;
+
+class NotifyBrrrOfWebMention implements ShouldQueue
+{
+    use Dispatchable, InteractsWithQueue, Queueable, SerializesModels;
+
+    /**
+     * Create a new job instance.
+     */
+    public function __construct(
+        protected WebMention $webMention
+    ) {}
+
+    /**
+     * Execute the job.
+     */
+    public function handle(): void
+    {
+        $webhookUrl = config('services.brrr.webhook_url');
+
+        if (blank($webhookUrl)) {
+            return;
+        }
+
+        Http::post($webhookUrl, [
+            'title' => $this->title(),
+            'message' => "From {$this->webMention->source}",
+            'open_url' => $this->webMention->target,
+        ]);
+    }
+
+    /**
+     * Build a notification title based on the webmention type.
+     */
+    private function title(): string
+    {
+        return match ($this->webMention->type) {
+            'in-reply-to' => 'New reply',
+            'like-of' => 'New like',
+            'repost-of' => 'New repost',
+            default => 'New webmention',
+        };
+    }
+}

app/Jobs/ProcessWebMention.php

@@ -96,6 +96,7 @@ class ProcessWebMention implements ShouldQueue
         $webmention->type = $type;
         $webmention->mf2 = json_encode($microformats);
         $webmention->save();
+        dispatch(new NotifyBrrrOfWebMention($webmention));
     }
 
     /**