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();
+    }
+}

src/Mentions/MentionParser.php

@@ -0,0 +1,52 @@
+<?php
+
+namespace Relaticle\Comments\Mentions;
+
+use Illuminate\Support\Collection;
+use Relaticle\Comments\Comment;
+use Relaticle\Comments\Config;
+use Relaticle\Comments\Contracts\MentionResolver;
+use Relaticle\Comments\Events\UserMentioned;
+
+class MentionParser
+{
+    public function __construct(
+        protected MentionResolver $resolver,
+    ) {}
+
+    /** @return Collection<int, int> */
+    public function parse(string $body): Collection
+    {
+        $text = html_entity_decode(strip_tags($body), ENT_QUOTES, 'UTF-8');
+
+        preg_match_all('/(?<=@)[\w]+/', $text, $matches);
+
+        $names = array_unique($matches[0] ?? []);
+
+        if (empty($names)) {
+            return collect();
+        }
+
+        return $this->resolver->resolveByNames($names)->pluck('id');
+    }
+
+    public function syncMentions(Comment $comment): void
+    {
+        $newMentionIds = $this->parse($comment->body);
+        $existingMentionIds = $comment->mentions()->pluck('comment_mentions.user_id');
+
+        $addedIds = $newMentionIds->diff($existingMentionIds);
+
+        $comment->mentions()->sync($newMentionIds->all());
+
+        $commenterModel = Config::getCommenterModel();
+
+        $addedIds->each(function ($userId) use ($comment, $commenterModel) {
+            $mentionedUser = $commenterModel::find($userId);
+
+            if ($mentionedUser) {
+                UserMentioned::dispatch($comment, $mentionedUser);
+            }
+        });
+    }
+}