feat: extract bookmarks as standalone module with MintyPHP\Module\Bookmarks namespace

Moves bookmarks from core hardcoding into modules/bookmarks/ as a
fully self-contained module, following the same pattern as addressbook.

Module contributions via platform slots:
- aside.tab_panel: bookmark sidebar panel
- topbar.right_item: bookmark toggle button
- layout.body_end_template: bookmark/group dialogs
- layout.head_style: bookmark CSS (form + sidebar)
- runtime.component: bookmark-save and bookmark-panel (phase: late)
- search.resource_item: bookmarks in global search (user-scoped via {{userId}})

Backend fully in module namespace (MintyPHP\Module\Bookmarks\*):
- Service: BookmarkService, BookmarkServicesFactory, BookmarkRepositoryFactory
- Repository: BookmarkRepository, BookmarkGroupRepository, BookmarkNavigationRepository
- Support: BookmarkUrlNormalizer
- Providers: BookmarksSessionProvider, BookmarksLayoutProvider, BookmarksSearchProvider

Core cleanup:
- Removed all bookmark-specific markup from core templates
- Removed core DI registrations for bookmark services
- Removed core bookmark pages, JS, CSS
- AuthSessionTenantContextService delegates to module SessionProvider

Architecture guards:
- NoBookmarksHardcodingTest: verifies zero bookmark references in core
- testModuleClassesUseModuleNamespace: prevents core namespace leakage

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

modules/bookmarks/lib/Module/Bookmarks/Providers/BookmarksSearchProvider.php

@@ -0,0 +1,53 @@
+<?php
+
+namespace MintyPHP\Module\Bookmarks\Providers;
+
+use MintyPHP\App\Module\Contracts\SearchResourceProvider;
+
+/**
+ * Provides the bookmarks search resource for the global search.
+ *
+ * Bookmarks are user-scoped: the SQL uses {{userId}} so only
+ * the current user's bookmarks are searched.
+ */
+final class BookmarksSearchProvider implements SearchResourceProvider
+{
+    public function resources(): array
+    {
+        return [
+            'bookmarks' => [
+                'label' => t('Bookmarks'),
+                'permission' => '',
+                'count_sql' => "SELECT COUNT(*) FROM user_bookmarks WHERE user_id = {{userId}} AND (name LIKE ? ESCAPE '\\\\' OR url LIKE ? ESCAPE '\\\\')",
+                'preview_sql' => "SELECT id, name, url FROM user_bookmarks WHERE user_id = {{userId}} AND (name LIKE ? ESCAPE '\\\\' OR url LIKE ? ESCAPE '\\\\') ORDER BY sort_order ASC LIMIT ?",
+                'result_sql' => "SELECT id, name, url FROM user_bookmarks WHERE user_id = {{userId}} AND (name LIKE ? ESCAPE '\\\\' OR url LIKE ? ESCAPE '\\\\') ORDER BY sort_order ASC",
+            ],
+        ];
+    }
+
+    public function mapResultItem(string $resourceKey, array $row): ?array
+    {
+        if ($resourceKey !== 'bookmarks') {
+            return null;
+        }
+
+        $name = trim((string) ($row['name'] ?? ''));
+        $url = trim((string) ($row['url'] ?? ''));
+
+        if ($name === '') {
+            return null;
+        }
+
+        return [
+            'title' => $name,
+            'subtitle' => $url,
+            'url' => $url !== '' ? $url : '#',
+            'icon' => 'bi-bookmark-star',
+        ];
+    }
+
+    public function listUrl(string $resourceKey, string $encodedSearch): string
+    {
+        return '';
+    }
+}