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/NannyOrder.php

@@ -0,0 +1,18 @@
+<?php
+namespace App\Models\Nanny;
+use App\Models\Crm\Customer;
+use App\Models\User;
+use App\Traits\BelongsToStore;
+use Illuminate\Database\Eloquent\Model;
+use Illuminate\Database\Eloquent\Relations\BelongsTo;
+use Illuminate\Database\Eloquent\Relations\HasMany;
+class NannyOrder extends Model
+{
+    use BelongsToStore;
+    protected $fillable = ['store_id','customer_id','nanny_id','order_no','service_type','start_date','end_date','days','price','status','match_candidates','remark','created_by'];
+    protected function casts(): array { return ['service_type'=>'integer','start_date'=>'date','end_date'=>'date','days'=>'integer','price'=>'decimal:2','status'=>'integer','match_candidates'=>'array']; }
+    public function customer(): BelongsTo { return $this->belongsTo(Customer::class); }
+    public function nanny(): BelongsTo { return $this->belongsTo(Nanny::class); }
+    public function creator(): BelongsTo { return $this->belongsTo(User::class, 'created_by'); }
+    public function reviews(): HasMany { return $this->hasMany(NannyReview::class); }
+}