feat: WBS-UX-03 FAQ 관리 기능 구현 — 어드민 CRUD + 홈페이지 DB 연동

DB:
- V007__CreateFaqs.sql: faqs 테이블 (question, answer, category,
  sort_order, is_active) + 기본 FAQ 4개 시드

Domain:
- Faq 엔티티
- IFaqRepository (GetActiveAsync, GetAllAsync, CRUD)

Infrastructure:
- FaqRepository: sort_order 정렬, CRUD

Application:
- FaqService: Categories 상수, Validate (질문·답변 필수)

Admin UI (Blazor):
- FaqList.razor: 전체 목록, 활성/비활성 상태 칩, 삭제 확인
- FaqEdit.razor: 질문/답변/카테고리/순서/활성 토글 폼
- MainLayout: 홈페이지 그룹 하위에 FAQ 관리 메뉴 추가

홈페이지:
- Index.cshtml 하드코딩 FAQ → ActiveFaqs DB 루프로 교체
- FAQ 없으면 섹션 전체 숨김 (빈 DB에 안전)
- IndexModel: FaqService 주입, Task.WhenAll 병렬 로드

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

TaxBaik.Infrastructure/DependencyInjection.cs

@@ -17,6 +17,7 @@ public static class DependencyInjection
         services.AddScoped<ISiteSettingRepository, SiteSettingRepository>();
         services.AddScoped<IAnnouncementRepository, AnnouncementRepository>();
         services.AddScoped<IClientRepository, ClientRepository>();
+        services.AddScoped<IFaqRepository, FaqRepository>();
 
         return services;
     }

TaxBaik.Infrastructure/Repositories/FaqRepository.cs

@@ -0,0 +1,60 @@
+namespace TaxBaik.Infrastructure.Repositories;
+
+using Dapper;
+using TaxBaik.Domain.Entities;
+using TaxBaik.Domain.Interfaces;
+
+public class FaqRepository(IDbConnectionFactory connectionFactory) : BaseRepository(connectionFactory), IFaqRepository
+{
+    private const string SelectColumns =
+        "id, question, answer, category, sort_order, is_active, created_at, updated_at";
+
+    public async Task<IEnumerable<Faq>> GetActiveAsync(CancellationToken ct = default)
+    {
+        using var conn = Conn();
+        return await conn.QueryAsync<Faq>(
+            $"SELECT {SelectColumns} FROM faqs WHERE is_active = TRUE ORDER BY sort_order, id");
+    }
+
+    public async Task<IEnumerable<Faq>> GetAllAsync(CancellationToken ct = default)
+    {
+        using var conn = Conn();
+        return await conn.QueryAsync<Faq>(
+            $"SELECT {SelectColumns} FROM faqs ORDER BY sort_order, id");
+    }
+
+    public async Task<Faq?> GetByIdAsync(int id, CancellationToken ct = default)
+    {
+        using var conn = Conn();
+        return await conn.QueryFirstOrDefaultAsync<Faq>(
+            $"SELECT {SelectColumns} FROM faqs WHERE id = @Id",
+            new { Id = id });
+    }
+
+    public async Task<int> CreateAsync(Faq faq, CancellationToken ct = default)
+    {
+        using var conn = Conn();
+        return await conn.QueryFirstAsync<int>(
+            @"INSERT INTO faqs (question, answer, category, sort_order, is_active, created_at, updated_at)
+              VALUES (@Question, @Answer, @Category, @SortOrder, @IsActive, NOW(), NOW())
+              RETURNING id",
+            faq);
+    }
+
+    public async Task UpdateAsync(Faq faq, CancellationToken ct = default)
+    {
+        using var conn = Conn();
+        await conn.ExecuteAsync(
+            @"UPDATE faqs
+              SET question = @Question, answer = @Answer, category = @Category,
+                  sort_order = @SortOrder, is_active = @IsActive, updated_at = NOW()
+              WHERE id = @Id",
+            faq);
+    }
+
+    public async Task DeleteAsync(int id, CancellationToken ct = default)
+    {
+        using var conn = Conn();
+        await conn.ExecuteAsync("DELETE FROM faqs WHERE id = @Id", new { Id = id });
+    }
+}