refactor: align addressbook module to MintyPHP\Module\AddressBook namespace

Migrates addressbook service classes from core namespace
(MintyPHP\Service\AddressBook\*) to proper module namespace
(MintyPHP\Module\AddressBook\Service\*), consistent with the
bookmarks module pattern.

Moved to module:
- AddressBookService → modules/addressbook/lib/Module/AddressBook/Service/
- AddressBookServicesFactory → modules/addressbook/lib/Module/AddressBook/Service/
- AddressBookServiceTest → modules/addressbook/tests/Module/AddressBook/Service/
- Pages, templates, CSS, JS all in module directory

All module PHP classes now live under MintyPHP\Module\<Name>\*,
enforced by ModuleStructureContractTest::testModuleClassesUseModuleNamespace.

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

modules/addressbook/lib/Module/AddressBook/Providers/AddressBookSessionProvider.php

@@ -0,0 +1,40 @@
+<?php
+
+namespace MintyPHP\Module\AddressBook\Providers;
+
+use MintyPHP\App\AppContainer;
+use MintyPHP\App\Module\Contracts\SessionProvider;
+use MintyPHP\Http\SessionStoreInterface;
+use MintyPHP\Service\User\UserTenantContextService;
+
+/**
+ * Populates session with department-by-tenant hierarchy data used by the
+ * address book aside panel.
+ */
+final class AddressBookSessionProvider implements SessionProvider
+{
+    public function populate(array $user, AppContainer $container): void
+    {
+        $userId = (int) ($user['id'] ?? 0);
+        if ($userId <= 0) {
+            unset($_SESSION['available_departments_by_tenant']);
+            return;
+        }
+
+        $tenantContext = $container->get(UserTenantContextService::class);
+        $sessionStore = $container->get(SessionStoreInterface::class);
+        if (!$tenantContext instanceof UserTenantContextService || !$sessionStore instanceof SessionStoreInterface) {
+            return;
+        }
+
+        $sessionStore->set(
+            'available_departments_by_tenant',
+            $tenantContext->getAvailableDepartmentsByTenant($userId)
+        );
+    }
+
+    public function clear(): void
+    {
+        unset($_SESSION['available_departments_by_tenant']);
+    }
+}