feat(booking): persist service duration and allow full service replacement

Appointment gains:
  - replaceServiceItems(): full replacement that unconditionally syncs the
    legacy single serviceItem column. addServiceItem() only fills it when null,
    which would leave stale service names in the four consumers that read
    service_item (admin lists, public site, desktop app).
  - currentServiceUuids(): input-order uuids, falling back to the single column
    for appointments created before multi-service support.
  - service_total_minutes / service_buffer_minutes (both nullable, NULL in slot
    mode). slot_end - slot_start carries the number but cannot say whether it
    was intentional, and a reserve entry has slot_start == slot_end so its
    duration had nowhere to live.

Existing columns untouched: slot_start, slot_end, active_slot_key, is_reserve
verified unchanged via SHOW COLUMNS.

Task: docs/new_feture/taskes/task-00-service-mode-completion/
Slot-mode contract: unchanged (--group=slot-mode-frozen green)

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

migrations/Version20260730091332.php

@@ -0,0 +1,35 @@
+<?php
+
+declare(strict_types=1);
+
+namespace DoctrineMigrations;
+
+use Doctrine\DBAL\Schema\Schema;
+use Doctrine\Migrations\AbstractMigration;
+
+/**
+ * حالت نوبت‌دهی سرویسی: مدت و بافرِ محاسبه‌شده در لحظهٔ ثبت را روی خودِ نوبت نگه می‌دارد.
+ *
+ * هر دو ستون تهی‌پذیرند و در حالت اسلاتی NULL می‌مانند؛ هیچ ستون موجودی حذف نمی‌شود،
+ * نوعش عوض نمی‌شود و معنایش تغییر نمی‌کند. `slot_start`/`slot_end`/`active_slot_key`
+ * دست‌نخورده‌اند (خط سرخ فاز موتور چندمنبعی).
+ *
+ * @see docs/new_feture/taskes/task-00-service-mode-completion/database.md
+ */
+final class Version20260730091332 extends AbstractMigration
+{
+    public function getDescription(): string
+    {
+        return 'Add service_total_minutes and service_buffer_minutes to appointments (service booking mode)';
+    }
+
+    public function up(Schema $schema): void
+    {
+        $this->addSql('ALTER TABLE appointments ADD service_total_minutes SMALLINT DEFAULT NULL, ADD service_buffer_minutes SMALLINT DEFAULT NULL');
+    }
+
+    public function down(Schema $schema): void
+    {
+        $this->addSql('ALTER TABLE appointments DROP service_total_minutes, DROP service_buffer_minutes');
+    }
+}