refactor: Web과 Admin 통합 - 단일 포트 5001로 운영

분리의 단점을 제거하고 단일 앱으로 통합:

구조 변경:
- TaxBaik.Admin → TaxBaik.Web/Components/Admin/
- Admin Services → TaxBaik.Web/Services/
- 포트: 5001 (기존 5002 제거)

경로:
- 홈페이지: http://localhost:5001/taxbaik
- 관리자: http://localhost:5001/taxbaik/admin

기술:
- Razor Pages (Web) + Blazor Server (Admin) 통합
- 단일 Program.cs로 양쪽 모두 지원
- JWT 인증 유지
- MudBlazor UI 유지

장점:
- 개발 복잡도 감소 (터미널 1개)
- 배포 단순화 (앱 1개)
- DB 마이그레이션 1회 실행

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

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

@@ -0,0 +1,64 @@
+@page "/admin/inquiries/{InquiryId:int}"
+@using TaxBaik.Domain.Interfaces
+@attribute [Authorize]
+@inject IInquiryRepository InquiryRepository
+@inject NavigationManager Navigation
+
+<PageTitle>문의 상세</PageTitle>
+
+@if (inquiry != null)
+{
+    <MudButton Variant="Variant.Text" @onclick="@(() => Navigation.NavigateTo("/taxbaik/admin/inquiries"))">
+        ← 돌아가기
+    </MudButton>
+
+    <MudPaper Class="pa-4 mt-4" Elevation="1">
+        <MudGrid>
+            <MudItem xs="12" md="6">
+                <MudText Typo="Typo.subtitle1">이름</MudText>
+                <MudText>@inquiry.Name</MudText>
+            </MudItem>
+            <MudItem xs="12" md="6">
+                <MudText Typo="Typo.subtitle1">연락처</MudText>
+                <MudText>@inquiry.Phone</MudText>
+            </MudItem>
+            <MudItem xs="12" md="6">
+                <MudText Typo="Typo.subtitle1">이메일</MudText>
+                <MudText>@inquiry.Email</MudText>
+            </MudItem>
+            <MudItem xs="12" md="6">
+                <MudText Typo="Typo.subtitle1">분야</MudText>
+                <MudText>@inquiry.ServiceType</MudText>
+            </MudItem>
+            <MudItem xs="12">
+                <MudText Typo="Typo.subtitle1">메시지</MudText>
+                <MudText>@inquiry.Message</MudText>
+            </MudItem>
+            <MudItem xs="12">
+                <MudText Typo="Typo.subtitle1">상태</MudText>
+                <MudSelect @bind-Value="inquiry.Status" Label="상태 변경">
+                    <MudSelectItem Value="@("new")">신규</MudSelectItem>
+                    <MudSelectItem Value="@("contacted")">연락함</MudSelectItem>
+                    <MudSelectItem Value="@("completed")">완료</MudSelectItem>
+                </MudSelect>
+            </MudItem>
+        </MudGrid>
+    </MudPaper>
+}
+else
+{
+    <MudText>문의를 찾을 수 없습니다.</MudText>
+}
+
+@code {
+    [Parameter]
+    public int InquiryId { get; set; }
+
+    private Domain.Entities.Inquiry inquiry;
+
+    protected override async Task OnInitializedAsync()
+    {
+        var (inquiries, _) = await InquiryRepository.GetPagedAsync(1, 1000);
+        inquiry = inquiries.FirstOrDefault(x => x.Id == InquiryId);
+    }
+}

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

@@ -0,0 +1,23 @@
+@page "/admin/inquiries"
+@using TaxBaik.Domain.Interfaces
+@attribute [Authorize]
+@inject IInquiryRepository InquiryRepository
+
+<PageTitle>문의 관리</PageTitle>
+
+<MudText Typo="Typo.h5" Class="mb-4">💬 문의 관리</MudText>
+
+<MudTabs>
+    <MudTabPanel Text="전체">
+        <InquiryTable Status="" />
+    </MudTabPanel>
+    <MudTabPanel Text="신규">
+        <InquiryTable Status="new" />
+    </MudTabPanel>
+    <MudTabPanel Text="연락함">
+        <InquiryTable Status="contacted" />
+    </MudTabPanel>
+    <MudTabPanel Text="완료">
+        <InquiryTable Status="completed" />
+    </MudTabPanel>
+</MudTabs>