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

src/Guides/GuideRepository.php

@@ -0,0 +1,51 @@
+<?php
+
+declare(strict_types=1);
+
+namespace LIT\MCP\Guides;
+
+/**
+ * Reads guide markdown files from one directory. Topic names are restricted to
+ * lowercase slugs, so no path outside the directory can ever be read.
+ */
+final class GuideRepository
+{
+    private const TOPIC_PATTERN = '/^[a-z0-9]+(?:-[a-z0-9]+)*$/';
+
+    public function __construct(private string $directory)
+    {
+    }
+
+    /** @return list<string> */
+    public function topics(): array
+    {
+        $files = glob($this->directory . '/*.md');
+        if ($files === false) {
+            return [];
+        }
+
+        $topics = [];
+        foreach ($files as $file) {
+            $topic = basename($file, '.md');
+            if (preg_match(self::TOPIC_PATTERN, $topic) === 1) {
+                $topics[] = $topic;
+            }
+        }
+        sort($topics);
+
+        return $topics;
+    }
+
+    public function get(string $topic): ?string
+    {
+        if (preg_match(self::TOPIC_PATTERN, $topic) !== 1 || ! in_array($topic, $this->topics(), true)) {
+            return null;
+        }
+
+        $path = $this->directory . '/' . $topic . '.md';
+        // phpcs:ignore WordPress.WP.AlternativeFunctions.file_get_contents_file_get_contents
+        $content = file_get_contents($path);
+
+        return $content === false ? null : $content;
+    }
+}

src/Guides/InstructionsBuilder.php

@@ -0,0 +1,40 @@
+<?php
+
+declare(strict_types=1);
+
+namespace LIT\MCP\Guides;
+
+use LIT\MCP\Integrations\Integration;
+use LIT\MCP\Integrations\IntegrationRegistry;
+
+/**
+ * Builds the short server instructions every MCP client loads on connect.
+ * Keep this text short: it occupies context in every conversation.
+ */
+final class InstructionsBuilder
+{
+    public function __construct(private IntegrationRegistry $registry)
+    {
+    }
+
+    public function build(): string
+    {
+        $active = implode(', ', array_map(
+            static fn (Integration $integration): string => $integration->id(),
+            $this->registry->available()
+        ));
+
+        return implode("\n", [
+            'LIT MCP pflegt diese WordPress-Website (Inhalte, Medien, Divi 5, Pods).',
+            'Aktive Integrationen: ' . $active . '.',
+            'Regeln:',
+            '- Vor dem ersten Arbeitsschritt lit-guide (ohne Topic) aufrufen; Details je Thema über lit-guide '
+                . 'mit topic.',
+            '- Änderungen erzeugen native Divi-Module; Variablen und Presets vor festen Werten; Code-Modul nur, '
+                . 'wenn kein natives Modul passt.',
+            '- Den Status (Entwurf/veröffentlicht) nie ändern, außer der Nutzer verlangt es ausdrücklich.',
+            '- Schreib-Tools verlangen den aktuellen rev-Wert aus dem letzten Lesevorgang.',
+            '- Fehler enthalten einen hint – ihm folgen, statt blind zu wiederholen.',
+        ]);
+    }
+}

src/Integrations/Core/GuideAbility.php

@@ -0,0 +1,94 @@
+<?php
+
+declare(strict_types=1);
+
+namespace LIT\MCP\Integrations\Core;
+
+use LIT\MCP\Abilities\Ability;
+use LIT\MCP\Abilities\Errors;
+use LIT\MCP\Guides\GuideRepository;
+use WP_Error;
+
+final class GuideAbility implements Ability
+{
+    private const DEFAULT_TOPIC = 'overview';
+
+    public function __construct(private GuideRepository $guides)
+    {
+    }
+
+    public function name(): string
+    {
+        return 'lit/guide';
+    }
+
+    public function label(): string
+    {
+        return 'Anleitung';
+    }
+
+    public function description(): string
+    {
+        return 'Liefert Anleitungen zur Bedienung dieses MCP-Servers. Ohne topic: Übersicht und Liste aller Themen.';
+    }
+
+    public function inputSchema(): array
+    {
+        return [
+            'type' => 'object',
+            'properties' => [
+                'topic' => [
+                    'type' => 'string',
+                    'description' => 'Thema, z. B. "overview" oder "divi-shortform".',
+                ],
+            ],
+            'additionalProperties' => false,
+        ];
+    }
+
+    public function outputSchema(): ?array
+    {
+        return [
+            'type' => 'object',
+            'properties' => [
+                'topic' => ['type' => 'string'],
+                'topics' => ['type' => 'array', 'items' => ['type' => 'string']],
+                'content' => ['type' => 'string'],
+            ],
+            'required' => ['topic', 'topics', 'content'],
+        ];
+    }
+
+    public function annotations(): array
+    {
+        return ['readonly' => true, 'destructive' => false, 'idempotent' => true];
+    }
+
+    public function isDirect(): bool
+    {
+        return true;
+    }
+
+    public function permission(array $input): bool|WP_Error
+    {
+        return true;
+    }
+
+    public function execute(array $input): mixed
+    {
+        $topic = isset($input['topic']) && is_string($input['topic']) && $input['topic'] !== ''
+            ? $input['topic']
+            : self::DEFAULT_TOPIC;
+        $topics = $this->guides->topics();
+        $content = $this->guides->get($topic);
+
+        if ($content === null) {
+            return Errors::notFound(sprintf(
+                'Unbekanntes Thema. Verfügbar: %s',
+                implode(', ', $topics)
+            ));
+        }
+
+        return ['topic' => $topic, 'topics' => $topics, 'content' => $content];
+    }
+}