feat: add EasyMDE markdown editor for blog creation/editing

- Add EasyMDE 2.18.0 CDN to App.razor
- Add Marked.js for markdown preview rendering
- Replace MudTextField with EasyMDE editor in BlogCreate.razor
- Replace MudTextField with EasyMDE editor in BlogEdit.razor
- Add JavaScript interop for editor initialization and content sync
- Support markdown syntax highlighting and formatting toolbar

Features:
✅ Bold, italic, strikethrough
✅ Headings (H1-H6)
✅ Code blocks and inline code
✅ Lists (ordered/unordered)
✅ Links and images
✅ Tables
✅ Quotes
✅ Horizontal rules
✅ Real-time preview (side-by-side mode)
✅ Full-screen editing
✅ Markdown guide

The editor syncs content with Blazor form on save.
Markdown syntax is preserved in database and rendered as HTML on blog pages.

TaxBaik.Web/Components/Admin/App.razor

@@ -11,6 +11,11 @@
     <link href="https://fonts.googleapis.com/css2?family=Noto+Sans+KR:wght@400;500;700&display=swap" rel="stylesheet" />
     <link href="https://fonts.googleapis.com/icon?family=Material+Icons" rel="stylesheet" />
     <link href="_content/MudBlazor/MudBlazor.min.css" rel="stylesheet" />
+    <!-- EasyMDE 마크다운 에디터 -->
+    <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/easymde@2.18.0/dist/easymde.min.css" />
+    <script src="https://cdn.jsdelivr.net/npm/easymde@2.18.0/dist/easymde.min.js"></script>
+    <!-- Marked 라이브러리 (EasyMDE 미리보기용) -->
+    <script src="https://cdn.jsdelivr.net/npm/marked@11.1.1/marked.min.js"></script>
     <script>
         document.documentElement.classList.toggle(
             'admin-login-route',

TaxBaik.Web/Components/Admin/Pages/Blog/BlogCreate.razor

@@ -33,24 +33,11 @@
             }
         </MudSelect>
 
-        <MudTabs Elevation="2" Rounded="true" ApplyEffectsToContainer="true" PanelClass="pa-4" Class="mb-4">
+        <div class="mb-4">
-            <MudTabPanel Text="에디터" Icon="@Icons.Material.Filled.Edit">
+            <label class="d-block mb-2" style="font-weight: 500;">본문 내용 (마크다운) *</label>
-                <MudTextField @bind-Value="model.Content" Label="본문 내용 *"
+            <textarea id="markdown-editor" @bind="model.Content" style="display: none;"></textarea>
-                    Variant="Variant.Outlined" Lines="15" Required="true" RequiredError="본문 내용을 입력하세요." Counter="10000" MaxLength="10000" HelperText="HTML 태그를 사용해 꾸밀 수 있습니다." />
+            <div id="editor-container" style="border: 1px solid #d0d0d0; border-radius: 4px; min-height: 400px;"></div>
-            </MudTabPanel>
-            <MudTabPanel Text="실시간 미리보기" Icon="@Icons.Material.Filled.Visibility">
-                <div class="border rounded pa-4 article-body lh-lg" style="min-height: 330px; max-height: 500px; overflow-y: auto; background-color: #fafafa;">
-                    @if (string.IsNullOrWhiteSpace(model.Content))
-                    {
-                        <p class="text-muted small text-center my-8">작성 중인 본문 내용이 이곳에 실시간으로 표시됩니다.</p>
-                    }
-                    else
-                    {
-                        @((MarkupString)model.Content)
-                    }
         </div>
-            </MudTabPanel>
-        </MudTabs>
 
         <MudTextField @bind-Value="model.Tags" Label="태그 (쉼표로 구분)"
             Variant="Variant.Outlined" Class="mb-4" />
@@ -74,12 +61,24 @@
     private MudForm? form;
     private List<Domain.Entities.Category> categories = [];
     private CreatePostModel model = new();
+    private EasyMDE.Editor? editor;
+
+    [Inject]
+    private IJSRuntime JS { get; set; } = null!;
 
     protected override async Task OnInitializedAsync()
     {
         categories = (await CategoryRepository.GetAllAsync()).ToList();
     }
 
+    protected override async Task OnAfterRenderAsync(bool firstRender)
+    {
+        if (firstRender)
+        {
+            await JS.InvokeVoidAsync("window.initMarkdownEditor", "markdown-editor", model.Content ?? "");
+        }
+    }
+
     private void GoBack()
     {
         Navigation.NavigateTo("/taxbaik/admin/blog");
@@ -90,6 +89,15 @@
         if (form == null)
             return;
 
+        // 에디터에서 최신 내용 가져오기
+        model.Content = await JS.InvokeAsync<string>("window.getMarkdownContent");
+
+        if (string.IsNullOrWhiteSpace(model.Content))
+        {
+            Snackbar.Add("본문 내용을 입력하세요.", Severity.Error);
+            return;
+        }
+
         await form.Validate();
         if (!form.IsValid)
             return;
@@ -127,3 +135,33 @@
         public bool IsPublished { get; set; }
     }
 }
+
+<!-- EasyMDE 초기화 스크립트 -->
+<script>
+    window.initMarkdownEditor = function(editorId, initialContent) {
+        if (!window.easyMDEInstance) {
+            window.easyMDEInstance = new EasyMDE({
+                element: document.getElementById(editorId),
+                spellChecker: false,
+                autoDownloadFontAwesome: false,
+                initialValue: initialContent || "",
+                toolbar: [
+                    "bold", "italic", "strikethrough", "|",
+                    "heading", "code", "|",
+                    "unordered-list", "ordered-list", "|",
+                    "link", "image", "table", "|",
+                    "quote", "horizontal-rule", "|",
+                    "preview", "side-by-side", "fullscreen", "|",
+                    "guide"
+                ],
+                previewRender: function(plainText) {
+                    return marked.parse(plainText);
+                }
+            });
+        }
+    };
+
+    window.getMarkdownContent = function() {
+        return window.easyMDEInstance ? window.easyMDEInstance.value() : "";
+    };
+</script>

TaxBaik.Web/Components/Admin/Pages/Blog/BlogEdit.razor

@@ -44,24 +44,11 @@ else
                 }
             </MudSelect>
 
-            <MudTabs Elevation="2" Rounded="true" ApplyEffectsToContainer="true" PanelClass="pa-4" Class="mb-4">
+            <div class="mb-4">
-                <MudTabPanel Text="에디터" Icon="@Icons.Material.Filled.Edit">
+                <label class="d-block mb-2" style="font-weight: 500;">본문 내용 (마크다운) *</label>
-                    <MudTextField @bind-Value="model.Content" Label="본문 내용 *"
+                <textarea id="markdown-editor" @bind="model.Content" style="display: none;"></textarea>
-                        Variant="Variant.Outlined" Lines="15" Required="true" RequiredError="본문 내용을 입력하세요." Counter="10000" MaxLength="10000" HelperText="HTML 태그를 사용해 꾸밀 수 있습니다." />
+                <div id="editor-container" style="border: 1px solid #d0d0d0; border-radius: 4px; min-height: 400px;"></div>
-                </MudTabPanel>
-                <MudTabPanel Text="실시간 미리보기" Icon="@Icons.Material.Filled.Visibility">
-                    <div class="border rounded pa-4 article-body lh-lg" style="min-height: 330px; max-height: 500px; overflow-y: auto; background-color: #fafafa;">
-                        @if (string.IsNullOrWhiteSpace(model.Content))
-                        {
-                            <p class="text-muted small text-center my-8">작성 중인 본문 내용이 이곳에 실시간으로 표시됩니다.</p>
-                        }
-                        else
-                        {
-                            @((MarkupString)model.Content)
-                        }
             </div>
-                </MudTabPanel>
-            </MudTabs>
 
             <MudTextField @bind-Value="model.Tags" Label="태그 (쉼표로 구분)"
                 Variant="Variant.Outlined" Class="mb-4" />
@@ -88,6 +75,9 @@ else
     [Parameter]
     public int Id { get; set; }
 
+    [Inject]
+    private IJSRuntime JS { get; set; } = null!;
+
     private MudForm? form;
     private Domain.Entities.BlogPost? post;
     private List<Domain.Entities.Category> categories = [];
@@ -115,6 +105,14 @@ else
         }
     }
 
+    protected override async Task OnAfterRenderAsync(bool firstRender)
+    {
+        if (firstRender && post != null)
+        {
+            await JS.InvokeVoidAsync("window.initMarkdownEditor", "markdown-editor", model.Content ?? "");
+        }
+    }
+
     private void MapPostToModel(Domain.Entities.BlogPost post)
     {
         model.Title = post.Title;
@@ -136,6 +134,15 @@ else
         if (form == null || post == null)
             return;
 
+        // 에디터에서 최신 내용 가져오기
+        model.Content = await JS.InvokeAsync<string>("window.getMarkdownContent");
+
+        if (string.IsNullOrWhiteSpace(model.Content))
+        {
+            Snackbar.Add("본문 내용을 입력하세요.", Severity.Error);
+            return;
+        }
+
         await form.Validate();
         if (!form.IsValid)
             return;
@@ -202,3 +209,33 @@ else
         public bool IsPublished { get; set; }
     }
 }
+
+<!-- EasyMDE 초기화 스크립트 -->
+<script>
+    window.initMarkdownEditor = function(editorId, initialContent) {
+        if (!window.easyMDEInstance) {
+            window.easyMDEInstance = new EasyMDE({
+                element: document.getElementById(editorId),
+                spellChecker: false,
+                autoDownloadFontAwesome: false,
+                initialValue: initialContent || "",
+                toolbar: [
+                    "bold", "italic", "strikethrough", "|",
+                    "heading", "code", "|",
+                    "unordered-list", "ordered-list", "|",
+                    "link", "image", "table", "|",
+                    "quote", "horizontal-rule", "|",
+                    "preview", "side-by-side", "fullscreen", "|",
+                    "guide"
+                ],
+                previewRender: function(plainText) {
+                    return marked.parse(plainText);
+                }
+            });
+        }
+    };
+
+    window.getMarkdownContent = function() {
+        return window.easyMDEInstance ? window.easyMDEInstance.value() : "";
+    };
+</script>