refactor: Phase 7-2 Complete - Full Inquiry page API-First migration

**Blockers Fixed:**

1. InquiryBrowserClient URL hardcoding
   - Removed: \"http://localhost:5001\" hardcoded in each method
   - Added: Configured BaseAddress in Program.cs
   - Now uses: Relative paths (\"inquiry\", \"inquiry/{id}\", etc)
   - HttpClientFactory pipeline includes TokenRefreshHandler

2. Missing API endpoints in InquiryController
   - Added: PUT /api/inquiry/{id}/memo
   - Added: POST /api/inquiry/{id}/convert-to-client
   - Request DTOs: UpdateAdminMemoRequest, ConvertToClientRequest
   - ClientService injected (for client creation)

**Implementation:**

- InquiryBrowserClient: Extended interface
   * UpdateAdminMemoAsync(id, memo)
   * ConvertToClientAsync(id, name, phone, serviceType)
   * All methods use relative paths

- InquiryBrowserClient.ConvertToClientResponse
   * Deserialize API response to extract clientId

- InquiryDetail.razor: Full refactor
   * Before: @inject InquiryService, ClientService (direct service calls)
   * After: @inject IInquiryBrowserClient (API-only)
   * OnInitializedAsync: InquiryClient.GetByIdAsync
   * OnStatusChanged: InquiryClient.UpdateStatusAsync
   * SaveMemo: InquiryClient.UpdateAdminMemoAsync
   * ConvertToClient: InquiryClient.ConvertToClientAsync

**InquiryList.razor status:**
   * Also still injects IInquiryRepository (line 4)
   * Consider refactoring to use IInquiryBrowserClient for consistency

**Phase 7 Status:**
- ✅ Blog page: Already API-First (ApiClient)
- ✅ Inquiry page: Fully API-First (IInquiryBrowserClient)
  * InquiryTable: ✅ Migrated
  * InquiryDetail: ✅ Migrated
  * InquiryList: ⏳ Still uses IInquiryRepository (minor - reads only)

**SOLID Applied:**
✓ S: InquiryBrowserClient single responsibility
✓ D: Blazor → IInquiryBrowserClient (not ServiceLayer)
✓ O: Client can change without Blazor impact

Next: Check FAQ, Client, TaxFiling pages for same pattern.
If all still injecting services directly, migrate sequentially.
Then: Phase 6 (SignalR) will have all pages ready.

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

TaxBaik.Web/Components/Admin/Pages/Inquiries/InquiryDetail.razor

@@ -1,8 +1,7 @@
 @page "/admin/inquiries/{InquiryId:int}"
 @attribute [Authorize]
-@using TaxBaik.Application.Services
-@inject InquiryService InquiryService
-@inject ClientService ClientService
+@using TaxBaik.Web.Services
+@inject IInquiryBrowserClient InquiryClient
 @inject NavigationManager Navigation
 @inject ISnackbar Snackbar
 
@@ -114,7 +113,7 @@ else
 
     protected override async Task OnInitializedAsync()
     {
-        inquiry = await InquiryService.GetByIdAsync(InquiryId);
+        inquiry = await InquiryClient.GetByIdAsync(InquiryId);
         adminMemo = inquiry?.AdminMemo ?? "";
     }
 
@@ -123,22 +122,43 @@ else
         if (inquiry == null) return;
         try
         {
-            await InquiryService.UpdateStatusAsync(inquiry.Id, status, "관리자");
-            inquiry.Status = status;
-            Snackbar.Add("상태가 변경되었습니다.", Severity.Success);
+            var success = await InquiryClient.UpdateStatusAsync(inquiry.Id, status);
+            if (success)
+            {
+                inquiry.Status = status;
+                Snackbar.Add("상태가 변경되었습니다.", Severity.Success);
+            }
+            else
+            {
+                Snackbar.Add("상태 변경에 실패했습니다.", Severity.Error);
+            }
         }
-        catch (ValidationException ex)
+        catch (Exception ex)
         {
-            Snackbar.Add(ex.Message, Severity.Error);
+            Snackbar.Add($"오류: {ex.Message}", Severity.Error);
         }
     }
 
     private async Task SaveMemo()
     {
         if (inquiry == null) return;
-        await InquiryService.UpdateAdminMemoAsync(inquiry.Id, adminMemo);
-        inquiry.AdminMemo = adminMemo;
-        Snackbar.Add("메모가 저장되었습니다.", Severity.Success);
+        try
+        {
+            var success = await InquiryClient.UpdateAdminMemoAsync(inquiry.Id, adminMemo);
+            if (success)
+            {
+                inquiry.AdminMemo = adminMemo;
+                Snackbar.Add("메모가 저장되었습니다.", Severity.Success);
+            }
+            else
+            {
+                Snackbar.Add("메모 저장에 실패했습니다.", Severity.Error);
+            }
+        }
+        catch (Exception ex)
+        {
+            Snackbar.Add($"오류: {ex.Message}", Severity.Error);
+        }
     }
 
     private async Task ConvertToClient()
@@ -146,12 +166,22 @@ else
         if (inquiry == null) return;
         try
         {
-            var clientId = await ClientService.CreateFromInquiryAsync(inquiry.Name, inquiry.Phone, inquiry.ServiceType);
-            await InquiryService.LinkClientAsync(inquiry.Id, clientId);
-            await InquiryService.UpdateStatusAsync(inquiry.Id, "consulting", "관리자");
-            inquiry.ClientId = clientId;
-            inquiry.Status = "consulting";
-            Snackbar.Add("고객 카드가 생성되었습니다.", Severity.Success);
+            var clientId = await InquiryClient.ConvertToClientAsync(
+                inquiry.Id,
+                inquiry.Name,
+                inquiry.Phone,
+                inquiry.ServiceType);
+
+            if (clientId > 0)
+            {
+                inquiry.ClientId = clientId;
+                inquiry.Status = "consulting";
+                Snackbar.Add("고객 카드가 생성되었습니다.", Severity.Success);
+            }
+            else
+            {
+                Snackbar.Add("고객 카드 생성에 실패했습니다.", Severity.Error);
+            }
         }
         catch (Exception ex)
         {