feat : 테이블 및 DB 마이그레이션 파일 추가

products
  - common_codes
  - parts
  - products
  - files
  - price_histories
  - boms
  - bom_items

  boards
  - boards
  - board_settings
  - posts
  - board_comments
  - board_files
  - post_custom_field_values

  permissions
  - menus
  - roles
  - user_menu_permissions
  - role_menu_permissions

  tenants
  - tenants
  - plans
  - subscriptions
  - payments

app/Models/Boards/Board.php

@@ -0,0 +1,21 @@
+<?php
+
+namespace App\Models\Boards;
+
+use Illuminate\Database\Eloquent\Model;
+
+class Board extends Model
+{
+    protected $table = 'boards';
+    protected $fillable = [
+        'tenant_id', 'board_code', 'name', 'description', 'editor_type',
+        'allow_files', 'max_file_count', 'max_file_size', 'extra_settings', 'is_active'
+    ];
+
+    public function customFields() {
+        return $this->hasMany(BoardSetting::class, 'board_id');
+    }
+    public function posts() {
+        return $this->hasMany(Post::class, 'board_id');
+    }
+}