fix:고객 검색을 TenantProspect(명함 등록 고객)에서 조회하도록 수정

- Tenant 대신 TenantProspect(tenant_prospects 테이블) 사용
- 업체명/사업자번호/대표자명/연락처로 검색
- 필드명 매칭: business_number, contact_phone, contact_email

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

app/Http/Controllers/ESign/EsignApiController.php

@@ -13,7 +13,7 @@
 use App\Models\ESign\EsignSigner;
 use App\Models\ESign\EsignSignField;
 use App\Models\ESign\EsignAuditLog;
-use App\Models\Tenants\Tenant;
+use App\Models\Sales\TenantProspect;
 use App\Models\Tenants\TenantSetting;
 use App\Services\Barobill\BarobillService;
 use App\Services\GoogleCloudStorageService;
@@ -75,33 +75,33 @@ public function searchPartners(Request $request): JsonResponse
     }
 
     /**
-     * 고객(테넌트) 검색
+     * 고객(명함 등록 고객) 검색
      */
     public function searchTenants(Request $request): JsonResponse
     {
         $q = trim($request->input('q', ''));
 
-        $query = Tenant::whereNull('deleted_at');
+        $query = TenantProspect::query();
 
         if ($q !== '') {
             $query->where(function ($w) use ($q) {
                 $w->where('company_name', 'like', "%{$q}%")
-                  ->orWhere('business_num', 'like', "%{$q}%")
-                  ->orWhere('phone', 'like', "%{$q}%")
-                  ->orWhere('ceo_name', 'like', "%{$q}%");
+                  ->orWhere('business_number', 'like', "%{$q}%")
+                  ->orWhere('ceo_name', 'like', "%{$q}%")
+                  ->orWhere('contact_phone', 'like', "%{$q}%");
             });
         }
 
-        $tenants = $query->orderBy('company_name')->limit(20)->get();
+        $prospects = $query->orderBy('company_name')->limit(20)->get();
 
-        $data = $tenants->map(fn($t) => [
-            'id' => $t->id,
-            'company_name' => $t->company_name,
-            'business_num' => $t->business_num,
-            'ceo_name' => $t->ceo_name,
-            'address' => $t->address,
-            'phone' => $t->phone,
-            'email' => $t->email,
+        $data = $prospects->map(fn($p) => [
+            'id' => $p->id,
+            'company_name' => $p->company_name,
+            'business_number' => $p->business_number,
+            'ceo_name' => $p->ceo_name,
+            'address' => $p->address,
+            'phone' => $p->contact_phone,
+            'email' => $p->contact_email,
         ]);
 
         return response()->json(['success' => true, 'data' => $data]);