feat: media usage finder and media-get tool

Usage search distinguishes certain (ID referenced) and possible (file URL
only) usages, hides titles the user cannot read, and keeps queries bounded.
MediaGuard checks per-attachment capabilities and refuses trashed media
unless the caller opts in.

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

src/Integrations/Media/MediaIntegration.php

@@ -0,0 +1,41 @@
+<?php
+
+declare(strict_types=1);
+
+namespace LIT\MCP\Integrations\Media;
+
+use LIT\MCP\ChangeLog\ChangeLog;
+use LIT\MCP\Integrations\Integration;
+use LIT\MCP\Integrations\WordPress\Schema\ContentSchema;
+use LIT\MCP\Limits;
+
+/**
+ * Media library tools (spec §6.3). Always available. $log and $limits are used by the
+ * write tools that follow (upload, update, delete).
+ */
+final class MediaIntegration implements Integration
+{
+    public function __construct(private ContentSchema $schema, private ChangeLog $log, private Limits $limits)
+    {
+    }
+
+    public function id(): string
+    {
+        return 'media';
+    }
+
+    public function isAvailable(): bool
+    {
+        return true;
+    }
+
+    public function abilities(): array
+    {
+        $presenter = new MediaPresenter();
+        $finder = new MediaUsageFinder(fn (): array => $this->schema->mediaFieldKeys());
+
+        return [
+            new MediaGetAbility($presenter, $finder),
+        ];
+    }
+}