feat: guide tool and server instructions

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01At3V6SjwbMe6eMzVGW3Hs7

tests/Fixtures/guides/divi-shortform.md

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+# Divi-Kurzform
+Testinhalt Kurzform.

tests/Fixtures/guides/overview.md

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+# Übersicht
+Testinhalt Übersicht.

tests/Unit/Guides/GuideRepositoryTest.php

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+<?php
+
+declare(strict_types=1);
+
+namespace LIT\MCP\Tests\Unit\Guides;
+
+use LIT\MCP\Guides\GuideRepository;
+use LIT\MCP\Tests\Unit\TestCase;
+
+final class GuideRepositoryTest extends TestCase
+{
+    private GuideRepository $guides;
+
+    protected function setUp(): void
+    {
+        parent::setUp();
+        $this->guides = new GuideRepository(dirname(__DIR__, 2) . '/Fixtures/guides');
+    }
+
+    public function testListsTopicsSortedWithoutExtension(): void
+    {
+        self::assertSame(['divi-shortform', 'overview'], $this->guides->topics());
+    }
+
+    public function testReturnsMarkdownOfKnownTopic(): void
+    {
+        self::assertStringContainsString('Testinhalt Kurzform', (string) $this->guides->get('divi-shortform'));
+    }
+
+    /**
+     * @dataProvider maliciousTopics
+     */
+    public function testRejectsAnythingThatIsNotAPlainTopicName(string $topic): void
+    {
+        self::assertNull($this->guides->get($topic));
+    }
+
+    /** @return array<string, array{string}> */
+    public static function maliciousTopics(): array
+    {
+        return [
+            'traversal' => ['../../wp-config'],
+            'with extension' => ['overview.md'],
+            'empty' => [''],
+            'absolute' => ['/etc/passwd'],
+            'unknown' => ['does-not-exist'],
+            'uppercase' => ['OVERVIEW'],
+        ];
+    }
+
+    public function testMissingDirectoryYieldsNoTopics(): void
+    {
+        self::assertSame([], (new GuideRepository('/nonexistent/dir'))->topics());
+    }
+}

tests/Unit/Guides/InstructionsBuilderTest.php

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+<?php
+
+declare(strict_types=1);
+
+namespace LIT\MCP\Tests\Unit\Guides;
+
+use LIT\MCP\Guides\InstructionsBuilder;
+use LIT\MCP\Integrations\Integration;
+use LIT\MCP\Integrations\IntegrationRegistry;
+use LIT\MCP\Tests\Unit\TestCase;
+use Mockery;
+
+final class InstructionsBuilderTest extends TestCase
+{
+    public function testNamesActiveIntegrationsAndCoreRules(): void
+    {
+        $core = Mockery::mock(Integration::class);
+        $core->allows('id')->andReturn('core');
+        $core->allows('isAvailable')->andReturn(true);
+
+        $text = (new InstructionsBuilder(new IntegrationRegistry($core)))->build();
+
+        self::assertStringContainsString('Aktive Integrationen: core', $text);
+        self::assertStringContainsString('lit-guide', $text);
+        self::assertStringContainsString('Status', $text);
+        self::assertLessThan(2000, strlen($text), 'Instructions must stay short – they are loaded in every conversation.');
+    }
+}

tests/Unit/Integrations/Core/GuideAbilityTest.php

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+<?php
+
+declare(strict_types=1);
+
+namespace LIT\MCP\Tests\Unit\Integrations\Core;
+
+use LIT\MCP\Guides\GuideRepository;
+use LIT\MCP\Integrations\Core\GuideAbility;
+use LIT\MCP\Tests\Unit\TestCase;
+use WP_Error;
+
+final class GuideAbilityTest extends TestCase
+{
+    private GuideAbility $ability;
+
+    protected function setUp(): void
+    {
+        parent::setUp();
+        $this->ability = new GuideAbility(new GuideRepository(dirname(__DIR__, 3) . '/Fixtures/guides'));
+    }
+
+    public function testWithoutTopicReturnsOverviewAndTopicList(): void
+    {
+        $result = $this->ability->execute([]);
+
+        self::assertSame('overview', $result['topic']);
+        self::assertSame(['divi-shortform', 'overview'], $result['topics']);
+        self::assertStringContainsString('Testinhalt Übersicht', $result['content']);
+    }
+
+    public function testReturnsRequestedTopic(): void
+    {
+        $result = $this->ability->execute(['topic' => 'divi-shortform']);
+
+        self::assertStringContainsString('Testinhalt Kurzform', $result['content']);
+    }
+
+    public function testUnknownTopicIsNotFoundErrorListingTopics(): void
+    {
+        $result = $this->ability->execute(['topic' => '../../wp-config']);
+
+        self::assertInstanceOf(WP_Error::class, $result);
+        self::assertSame('lit_not_found', $result->get_error_code());
+        self::assertStringContainsString('divi-shortform', $result->get_error_message());
+    }
+
+    public function testIsDirectReadOnlyTool(): void
+    {
+        self::assertSame('lit/guide', $this->ability->name());
+        self::assertTrue($this->ability->isDirect());
+        self::assertTrue($this->ability->annotations()['readonly']);
+    }
+}