feat: implement admin inquiry create/edit/delete functionality

Core Components:
- Create reusable InquiryForm.razor component following SOLID principles
- Implement InquiryCreate.razor for registering new inquiries (offline, phone)
- Implement InquiryEdit.razor for modifying existing inquiries with delete
- Add DeleteAsync method to InquiryRepository and InquiryService
- Update InquiryList with 'Create' button and Edit link in table

Architecture:
- InquiryForm: Encapsulates form logic, can be reused for create/edit
- Service Layer: All operations go through InquiryService for cache invalidation
- Repository Pattern: Database operations isolated in InquiryRepository
- UI Consistency: Both pages follow admin-page-hero pattern

Features:
- Admin can create inquiries from phone/offline consultations
- Admin can modify inquiry details (name, phone, email, message, status, memo)
- Admin can delete inquiries with confirmation dialog
- All operations update dashboard cache
- Status validation and error handling throughout

Testing:
- Updated FakeInquiryRepository in tests to implement DeleteAsync

TaxBaik.Infrastructure/Repositories/InquiryRepository.cs

@@ -119,4 +119,10 @@ public class InquiryRepository(IDbConnectionFactory connectionFactory) : BaseRep
             "UPDATE inquiries SET client_id = @ClientId, updated_at = NOW() WHERE id = @Id",
             new { Id = inquiryId, ClientId = clientId });
     }
+
+    public async Task DeleteAsync(int id, CancellationToken cancellationToken = default)
+    {
+        using var conn = Conn();
+        await conn.ExecuteAsync("DELETE FROM inquiries WHERE id = @Id", new { Id = id });
+    }
 }