feat: 第三阶段业务模块(服务产康/月嫂/进销存)

- 新增3个migration(15张表): service/nanny/inventory
- 新增15个Model + 13个Controller
- 新增55条API路由(总计212条)
- 新增3个前端API模块 + 11个管理页面
- vite build验证通过

backend/app/Models/Nanny/NannyReview.php

@@ -0,0 +1,14 @@
+<?php
+namespace App\Models\Nanny;
+use App\Models\Crm\Customer;
+use Illuminate\Database\Eloquent\Model;
+use Illuminate\Database\Eloquent\Relations\BelongsTo;
+class NannyReview extends Model
+{
+    const UPDATED_AT = null;
+    protected $fillable = ['nanny_order_id','customer_id','nanny_id','score','content'];
+    protected function casts(): array { return ['score'=>'integer']; }
+    public function order(): BelongsTo { return $this->belongsTo(NannyOrder::class, 'nanny_order_id'); }
+    public function customer(): BelongsTo { return $this->belongsTo(Customer::class); }
+    public function nanny(): BelongsTo { return $this->belongsTo(Nanny::class); }
+}