Move webmention parsing and authorship into the app

The jonnybarnes/webmentions-parser package is now archived, and its
guzzlehttp/guzzle ^6|^7 constraint was the only thing holding Guzzle
back from 8. Port the parts we use into App\Services\WebMention and
drop the package.

Parser keeps getMentionType and the checkInReplyTo/LikeOf/RepostOf
checks unchanged. Authorship follows the same authorship algorithm,
with some fixes:

- fetch the author page with Laravel's Http client, so tests can fake
  it, and treat connection failures as AuthorshipParserException too
- keep state in locals so one instance can be reused safely
- make the url == uid == author-page check actually compare the
  h-card's uid, rather than an undefined variable

Add direct tests for both, and mark the library as archived on the
projects page.

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

tests/Unit/Services/WebMention/ParserTest.php

@@ -0,0 +1,89 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Tests\Unit\Services\WebMention;
+
+use App\Exceptions\InvalidMentionException;
+use App\Services\WebMention\Parser;
+use PHPUnit\Framework\Attributes\DataProvider;
+use PHPUnit\Framework\Attributes\Test;
+use Tests\TestCase;
+
+class ParserTest extends TestCase
+{
+    private const string TARGET = 'https://jonnybarnes.uk/notes/A';
+
+    private function entry(array $properties): array
+    {
+        return ['items' => [['type' => ['h-entry'], 'properties' => $properties]]];
+    }
+
+    public static function mentionTypes(): array
+    {
+        return [
+            'reply' => ['in-reply-to'],
+            'like' => ['like-of'],
+            'repost' => ['repost-of'],
+        ];
+    }
+
+    #[Test]
+    #[DataProvider('mentionTypes')]
+    public function it_determines_the_mention_type(string $type): void
+    {
+        $this->assertSame($type, (new Parser)->getMentionType($this->entry([$type => [self::TARGET]])));
+    }
+
+    #[Test]
+    public function it_finds_the_mention_type_in_nested_microformats(): void
+    {
+        $mf = ['items' => [['type' => ['h-feed'], 'children' => [
+            ['type' => ['h-entry'], 'properties' => ['like-of' => [self::TARGET]]],
+        ]]]];
+
+        $this->assertSame('like-of', (new Parser)->getMentionType($mf));
+    }
+
+    #[Test]
+    public function it_throws_when_the_mention_type_cannot_be_determined(): void
+    {
+        $this->expectException(InvalidMentionException::class);
+
+        (new Parser)->getMentionType($this->entry(['content' => ['Just a post']]));
+    }
+
+    #[Test]
+    public function it_checks_a_reply_url_matches_the_target(): void
+    {
+        $parser = new Parser;
+
+        $this->assertTrue($parser->checkInReplyTo($this->entry(['in-reply-to' => [self::TARGET]]), self::TARGET));
+        $this->assertFalse($parser->checkInReplyTo($this->entry(['in-reply-to' => ['https://example.org/other']]), self::TARGET));
+        $this->assertFalse($parser->checkInReplyTo($this->entry(['content' => ['No reply']]), self::TARGET));
+    }
+
+    #[Test]
+    public function it_checks_a_reply_context_h_cite_matches_the_target(): void
+    {
+        $hCite = fn (string $url): array => ['type' => ['h-cite'], 'properties' => ['url' => [$url]]];
+        $parser = new Parser;
+
+        $this->assertTrue($parser->checkInReplyTo($this->entry(['in-reply-to' => [$hCite(self::TARGET)]]), self::TARGET));
+        $this->assertFalse($parser->checkInReplyTo($this->entry(['in-reply-to' => [$hCite('https://example.org/other')]]), self::TARGET));
+    }
+
+    #[Test]
+    public function it_checks_likes_and_reposts_match_the_target(): void
+    {
+        $parser = new Parser;
+
+        $this->assertTrue($parser->checkLikeOf($this->entry(['like-of' => [self::TARGET]]), self::TARGET));
+        $this->assertFalse($parser->checkLikeOf($this->entry(['like-of' => ['https://example.org/other']]), self::TARGET));
+        $this->assertFalse($parser->checkLikeOf($this->entry(['repost-of' => [self::TARGET]]), self::TARGET));
+
+        $this->assertTrue($parser->checkRepostOf($this->entry(['repost-of' => [self::TARGET]]), self::TARGET));
+        $this->assertFalse($parser->checkRepostOf($this->entry(['repost-of' => ['https://example.org/other']]), self::TARGET));
+        $this->assertFalse($parser->checkRepostOf($this->entry(['like-of' => [self::TARGET]]), self::TARGET));
+    }
+}