feat: add multi-company Feishu integration and data migration

- Add companies table enhancements (abbr, tenant_key, feishu_enabled)
- Add users table enhancements (feishu fields, sn, report_to, etc.)
- Create company_feishu_apps table for multi-app per company
- Create user_sn_pool table for user number management
- Update FeishuService to support multiple Feishu apps per company
- Add data migration script (002_merge_old_data.sql)
- Add import script (scripts/import_old_data.php)
- Update User and Company models with new scopes and relationships
- Add CompanyFeishuApp model
- Add Git workflow documentation (GIT_WORKFLOW.md)

This supports:
- Multi-company architecture with Feishu integration
- Multiple Feishu apps per company (X-Server, Ticket, CRM)
- User number assignment system
- Data migration from old project

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

backend/app/Model/Company.php

@@ -6,25 +6,32 @@ use support\Model;
 
 class Company extends Model
 {
-    protected $table = 'company';
+    protected $table = 'companies';
 
     protected $fillable = [
         'name',
-        'feishu_app_id',
-        'feishu_app_secret',
-        'feishu_tenant_key',
+        'abbr',
+        'tenant_key',
+        'sort',
         'status',
+        'feishu_enabled',
     ];
 
     protected $casts = [
+        'sort' => 'integer',
         'status' => 'integer',
+        'feishu_enabled' => 'boolean',
         'created_at' => 'datetime',
         'updated_at' => 'datetime',
     ];
 
-    protected $hidden = [
-        'feishu_app_secret',
-    ];
+    /**
+     * 关联用户
+     */
+    public function users()
+    {
+        return $this->hasMany(User::class, 'company_id');
+    }
 
     /**
      * 获取启用的公司
@@ -35,18 +42,52 @@ class Company extends Model
     }
 
     /**
-     * 根据飞书租户Key查找
+     * 根据租户Key查找
      */
-    public function scopeByFeishuTenantKey($query, string $tenantKey)
+    public function scopeByTenantKey($query, string $tenantKey)
     {
-        return $query->where('feishu_tenant_key', $tenantKey);
+        return $query->where('tenant_key', $tenantKey);
     }
 
     /**
-     * 根据飞书AppID查找
+     * 根据缩写查找
      */
-    public function scopeByFeishuAppId($query, string $appId)
+    public function scopeByAbbr($query, string $abbr)
     {
-        return $query->where('feishu_app_id', $appId);
+        return $query->where('abbr', $abbr);
+    }
+
+    /**
+     * 搜索公司
+     */
+    public function scopeSearch($query, ?string $keyword)
+    {
+        if (!$keyword) {
+            return $query;
+        }
+
+        return $query->where(function ($q) use ($keyword) {
+            $q->where('name', 'like', "%{$keyword}%")
+                ->orWhere('abbr', 'like', "%{$keyword}%");
+        });
+    }
+
+    /**
+     * 获取飞书应用配置
+     */
+    public function feishuApps()
+    {
+        return $this->hasMany(CompanyFeishuApp::class, 'company_id');
+    }
+
+    /**
+     * 获取默认飞书应用（X-Server）
+     */
+    public function getDefaultFeishuApp()
+    {
+        return $this->hasOne(CompanyFeishuApp::class, 'company_id')
+            ->where('system_id', 1)
+            ->where('status', 1)
+            ->orderBy('sort');
     }
 }