feat: initial release of relaticle/comments

Filament comments package with:
- Polymorphic commenting on any Eloquent model
- Threaded replies with configurable depth
- @mentions with autocomplete and user search
- Emoji reactions with toggle and who-reacted tooltips
- File attachments via Livewire uploads
- Reply and mention notifications via Filament notification system
- Thread subscriptions for notification control
- Real-time broadcasting (opt-in Echo) with polling fallback
- Dark mode support
- CommentsAction, CommentsTableAction, CommentsEntry for Filament integration
- 204 tests, 421 assertions

src/Mentions/DefaultMentionResolver.php

@@ -0,0 +1,32 @@
+<?php
+
+namespace Relaticle\Comments\Mentions;
+
+use Illuminate\Database\Eloquent\Model;
+use Illuminate\Support\Collection;
+use Relaticle\Comments\Config;
+use Relaticle\Comments\Contracts\MentionResolver;
+
+class DefaultMentionResolver implements MentionResolver
+{
+    /** @return Collection<int, Model> */
+    public function search(string $query): Collection
+    {
+        $model = Config::getCommenterModel();
+
+        return $model::query()
+            ->where('name', 'like', "{$query}%")
+            ->limit(Config::getMentionMaxResults())
+            ->get();
+    }
+
+    /** @return Collection<int, Model> */
+    public function resolveByNames(array $names): Collection
+    {
+        $model = Config::getCommenterModel();
+
+        return $model::query()
+            ->whereIn('name', $names)
+            ->get();
+    }
+}