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>

tests/Unit/Module/BookmarksAuthorizationPolicyTest.php

@@ -0,0 +1,45 @@
+<?php
+
+namespace MintyPHP\Tests\Unit\Module;
+
+use MintyPHP\Module\Bookmarks\BookmarksAuthorizationPolicy;
+use MintyPHP\Service\Access\AuthorizationPolicyInterface;
+use PHPUnit\Framework\TestCase;
+
+final class BookmarksAuthorizationPolicyTest extends TestCase
+{
+    public function testImplementsAuthorizationPolicyContract(): void
+    {
+        $policy = new BookmarksAuthorizationPolicy();
+        self::assertInstanceOf(AuthorizationPolicyInterface::class, $policy);
+    }
+
+    public function testSupportsBookmarksAbilityOnly(): void
+    {
+        $policy = new BookmarksAuthorizationPolicy();
+
+        self::assertTrue($policy->supports(BookmarksAuthorizationPolicy::ABILITY_USE));
+        self::assertFalse($policy->supports('addressbook.view'));
+    }
+
+    public function testAuthorizeAllowsAuthenticatedActors(): void
+    {
+        $policy = new BookmarksAuthorizationPolicy();
+
+        $decision = $policy->authorize(BookmarksAuthorizationPolicy::ABILITY_USE, [
+            'actor_user_id' => 7,
+        ]);
+
+        self::assertTrue($decision->isAllowed());
+    }
+
+    public function testAuthorizeDeniesMissingActor(): void
+    {
+        $policy = new BookmarksAuthorizationPolicy();
+
+        $decision = $policy->authorize(BookmarksAuthorizationPolicy::ABILITY_USE, []);
+
+        self::assertFalse($decision->isAllowed());
+        self::assertSame(403, $decision->status());
+    }
+}