feat: [outbound] 배차차량 관리 API — CRUD + options JSON 정책

- VehicleDispatchService: index(검색/필터/페이지네이션), stats(선불/착불/합계), show, update
- VehicleDispatchController + VehicleDispatchUpdateRequest
- options JSON 컬럼 추가 (dispatch_no, status, freight_cost_type, supply_amount, vat, total_amount, writer)
- ShipmentService.syncDispatches에 options 필드 지원 추가
- inventory.php에 vehicle-dispatches 라우트 4개 등록

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

database/migrations/2026_03_04_150000_add_options_to_shipment_vehicle_dispatches_table.php

@@ -0,0 +1,23 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+return new class extends Migration
+{
+    public function up(): void
+    {
+        Schema::table('shipment_vehicle_dispatches', function (Blueprint $table) {
+            $table->json('options')->nullable()->after('remarks')
+                ->comment('추가 속성 (dispatch_no, status, freight_cost_type, supply_amount, vat, total_amount, writer)');
+        });
+    }
+
+    public function down(): void
+    {
+        Schema::table('shipment_vehicle_dispatches', function (Blueprint $table) {
+            $table->dropColumn('options');
+        });
+    }
+};