feat(documents): 3-pane 중앙 리더 markdown-first 일원화 (DocumentViewer)

메인 /documents 3-pane 의 중앙 리더(DocumentViewer)가 md_content 를 안 쓰고
PDF=raw iframe·md/txt=plain marked(extracted_text)만 렌더하던 이원화 제거.
"전부 MD화" 한 canonical markdown 이 전체보기 없이 메인에서 바로 보이게 함(불만①).

- viewerType.ts 신설: 분류 단일 source(상세페이지와 공유 예정, drift 차단).
  csv/json/xml/html→text(<pre>, 콤마 뭉침 회피), office→preview-pdf, hwp→hwp-markdown.
- DocumentViewer: 자체 getViewerType/renderMd(본문) 제거 → viewerType.ts + MarkdownDoc.
  - pdf: canShowMarkdown(isMdSuccess+md_content) 시 MarkdownDoc 기본 + [Markdown|PDF원본]
    토글 + MarkdownStatusBadge, 아니면 PDF iframe. lastDocId 가드는 fullDoc.id(prop) 키잉.
  - markdown(md/txt): MarkdownDoc(extracted_text=표시·편집 단일 필드), 편집 유지.
  - hwp-markdown/article: MarkdownDoc(앵커/KaTeX/이미지). 편집 미리보기만 plain marked 유지.
  - article/preview-pdf/image/text/cad/synology/unsupported 분기 보존(회귀 금지) + synology 신설.

API md_status='completed'(S1 validator live) 대응 = isMdSuccess. FE only, BE/스키마 무변.
vite build + lint:tokens(신규 위반 0) PASS. 후속: 개요 rail·안전점프(commit 2), [id] 정합(commit 3).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

frontend/src/lib/components/DocumentViewer.svelte

@@ -3,10 +3,14 @@
   import { addToast } from '$lib/stores/toast';
   import { marked } from 'marked';
   import DOMPurify from 'dompurify';
-  import { ExternalLink, Save, RefreshCw } from 'lucide-svelte';
+  import { ExternalLink, Save } from 'lucide-svelte';
   import Tabs from '$lib/components/ui/Tabs.svelte';
+  import MarkdownDoc from '$lib/components/MarkdownDoc.svelte';
+  import MarkdownStatusBadge from '$lib/components/MarkdownStatusBadge.svelte';
+  import { getViewerType } from '$lib/utils/viewerType';
+  import { isMdSuccess } from '$lib/utils/mdStatus';
 
-  // marked + sanitize
+  // 편집 미리보기 전용 plain marked (본문 렌더는 MarkdownDoc 가 담당).
   marked.use({ mangle: false, headerIds: false });
   function renderMd(text) {
     return DOMPurify.sanitize(marked(text), {
@@ -22,33 +26,19 @@
   let loading = $state(true);
   let viewerType = $state('none');
 
-  // Markdown 편집
+  // Markdown 편집 (md/txt — extracted_text 가 표시·편집 단일 필드)
   let editMode = $state(false);
   let editContent = $state('');
   let editTab = $state('edit');
   let saving = $state(false);
   let rawMarkdown = $state('');
 
-  function getViewerType(format) {
-    if (['md', 'txt'].includes(format)) return 'markdown';
-    if (format === 'pdf') return 'pdf';
-    if (['hwp', 'hwpx'].includes(format)) return 'preview-pdf';
-    if (['odoc', 'osheet', 'docx', 'xlsx', 'pptx', 'odt', 'ods', 'odp'].includes(format)) return 'preview-pdf';
-    if (['jpg', 'jpeg', 'png', 'gif', 'bmp', 'tiff'].includes(format)) return 'image';
-    if (['csv', 'json', 'xml', 'html'].includes(format)) return 'text';
-    if (['dwg', 'dxf'].includes(format)) return 'cad';
-    return 'unsupported';
-  }
-
   const ODF_FORMATS = ['ods', 'odt', 'odp', 'odoc', 'osheet'];
 
-  function getEditInfo(doc) {
-    // DB에 저장된 편집 URL 우선
-    if (doc.edit_url) return { url: doc.edit_url, label: '편집' };
-    // ODF 포맷 → Synology Drive
-    if (ODF_FORMATS.includes(doc.file_format)) return { url: 'https://link.hyungi.net', label: 'Synology Drive에서 열기' };
-    // CAD
-    if (['dwg', 'dxf'].includes(doc.file_format)) return { url: 'https://web.autocad.com', label: 'AutoCAD Web' };
+  function getEditInfo(d) {
+    if (d.edit_url) return { url: d.edit_url, label: '편집' };
+    if (ODF_FORMATS.includes(d.file_format)) return { url: 'https://link.hyungi.net', label: 'Synology Drive에서 열기' };
+    if (['dwg', 'dxf'].includes(d.file_format)) return { url: 'https://web.autocad.com', label: 'AutoCAD Web' };
     return null;
   }
 
@@ -61,18 +51,17 @@
 
   async function loadFullDoc(id) {
     loading = true;
+    rawMarkdown = '';
     try {
       fullDoc = await api(`/documents/${id}`);
-      viewerType = fullDoc.source_channel === 'news' ? 'article' : getViewerType(fullDoc.file_format);
+      viewerType = getViewerType(fullDoc.file_format, fullDoc.source_channel);
 
-      // Markdown: extracted_text 없으면 원본 파일 직접 가져오기
+      // 본문 markdown(md/txt) 인데 extracted_text 가 비면 원본 파일 직접 로드.
       if (viewerType === 'markdown' && !fullDoc.extracted_text) {
         try {
           const resp = await fetch(`/api/documents/${id}/file?token=${getAccessToken()}`);
           if (resp.ok) rawMarkdown = await resp.text();
         } catch (e) { rawMarkdown = ''; }
-      } else {
-        rawMarkdown = '';
       }
     } catch (err) {
       fullDoc = null;
@@ -82,6 +71,23 @@
     }
   }
 
+  // PDF markdown-first: marker 가 만든 canonical md_content 가 있으면 기본으로 그것을 보여주고
+  // "PDF 원본" 토글 제공. lastDocId 는 prop(fullDoc.id) 로 키잉 — 3-pane 은 라우트 리마운트가
+  // 없어 page.params 가드는 no-op 이 된다.
+  let pdfViewMode = $state('markdown');
+  let lastDocId = $state(null);
+  let canShowMarkdown = $derived(
+    !!(isMdSuccess(fullDoc?.md_status) && fullDoc?.md_content?.trim())
+  );
+  $effect(() => {
+    if (!fullDoc) return;
+    if (fullDoc.id !== lastDocId) {
+      lastDocId = fullDoc.id;
+      pdfViewMode = canShowMarkdown ? 'markdown' : 'pdf';
+    }
+    if (!canShowMarkdown && pdfViewMode === 'markdown') pdfViewMode = 'pdf';
+  });
+
   function startEdit() {
     editContent = fullDoc?.extracted_text || rawMarkdown || '';
     editMode = true;
@@ -113,6 +119,7 @@
   }
 
   let editInfo = $derived(fullDoc ? getEditInfo(fullDoc) : null);
+  const PROSE = 'prose prose-invert prose-base max-w-none';
 </script>
 
 <svelte:window on:keydown={handleKeydown} />
@@ -125,38 +132,22 @@
       <div class="flex items-center gap-2">
         {#if viewerType === 'markdown'}
           {#if editMode}
-            <button
-              onclick={saveContent}
-              disabled={saving}
-              class="flex items-center gap-1 px-2 py-1 text-xs bg-accent text-white rounded hover:bg-accent-hover disabled:opacity-50"
-            >
+            <button onclick={saveContent} disabled={saving}
+              class="flex items-center gap-1 px-2 py-1 text-xs bg-accent text-white rounded hover:bg-accent-hover disabled:opacity-50">
               <Save size={12} /> {saving ? '저장 중...' : '저장'}
             </button>
-            <button
-              onclick={() => editMode = false}
-              class="px-2 py-1 text-xs text-dim hover:text-text"
-            >취소</button>
+            <button onclick={() => editMode = false} class="px-2 py-1 text-xs text-dim hover:text-text">취소</button>
           {:else}
-            <button
-              onclick={startEdit}
-              class="px-2 py-1 text-xs text-dim hover:text-accent border border-default rounded"
-            >편집</button>
+            <button onclick={startEdit} class="px-2 py-1 text-xs text-dim hover:text-accent border border-default rounded">편집</button>
           {/if}
         {/if}
         {#if editInfo}
-          <a
-            href={editInfo.url}
-            target="_blank"
-            rel="noopener"
-            class="flex items-center gap-1 px-2 py-1 text-xs text-dim hover:text-accent border border-default rounded"
-          >
+          <a href={editInfo.url} target="_blank" rel="noopener"
+            class="flex items-center gap-1 px-2 py-1 text-xs text-dim hover:text-accent border border-default rounded">
             <ExternalLink size={12} /> {editInfo.label}
           </a>
         {/if}
-        <a
-          href="/documents/{fullDoc.id}"
-          class="px-2 py-1 text-xs text-dim hover:text-accent border border-default rounded"
-        >전체 보기</a>
+        <a href="/documents/{fullDoc.id}" class="px-2 py-1 text-xs text-dim hover:text-accent border border-default rounded">전체 보기</a>
       </div>
     </div>
   {/if}
@@ -164,109 +155,130 @@
   <!-- 뷰어 본문 -->
   <div class="flex-1 overflow-auto min-h-0">
     {#if loading}
-      <div class="flex items-center justify-center h-full">
-        <p class="text-sm text-dim">로딩 중...</p>
-      </div>
+      <div class="flex items-center justify-center h-full"><p class="text-sm text-dim">로딩 중...</p></div>
     {:else if fullDoc}
       {#if viewerType === 'markdown'}
         {#if editMode}
-          <!-- Markdown 편집 (Tabs 프리미티브 — E.4) -->
           <div class="flex flex-col h-full">
-            <Tabs
-              tabs={[
-                { id: 'edit', label: '편집' },
-                { id: 'preview', label: '미리보기' },
-              ]}
-              bind:value={editTab}
-              class="flex flex-col h-full"
-            >
+            <Tabs tabs={[{ id: 'edit', label: '편집' }, { id: 'preview', label: '미리보기' }]} bind:value={editTab} class="flex flex-col h-full">
               {#snippet children(activeId)}
                 {#if activeId === 'edit'}
-                  <textarea
-                    bind:value={editContent}
+                  <textarea bind:value={editContent}
                     class="flex-1 w-full p-4 bg-bg text-text text-sm font-mono resize-none outline-none min-h-[300px]"
-                    spellcheck="false"
-                    aria-label="마크다운 편집"
-                  ></textarea>
+                    spellcheck="false" aria-label="마크다운 편집"></textarea>
                 {:else}
-                  <div class="flex-1 overflow-auto p-4 markdown-body">
-                    {@html renderMd(editContent)}
-                  </div>
+                  <div class="flex-1 overflow-auto p-4 markdown-body">{@html renderMd(editContent)}</div>
                 {/if}
               {/snippet}
             </Tabs>
           </div>
         {:else}
-          <div class="p-4 markdown-body">
-            {@html renderMd(fullDoc.extracted_text || rawMarkdown || '*텍스트 추출 대기 중*')}
+          <!-- md/txt = extracted_text 단일 필드(표시=편집), MarkdownDoc 로 앵커/KaTeX/이미지 렌더 -->
+          <div class="p-4">
+            <MarkdownDoc
+              documentId={fullDoc.id}
+              mdContent={null}
+              mdStatus={fullDoc.md_status}
+              mdExtractionError={fullDoc.md_extraction_error}
+              mdExtractionQuality={fullDoc.md_extraction_quality}
+              extractedText={fullDoc.extracted_text || rawMarkdown}
+              class={PROSE}
+            />
           </div>
         {/if}
       {:else if viewerType === 'pdf'}
-        <iframe
-          src="/api/documents/{fullDoc.id}/file?token={getAccessToken()}"
-          class="w-full h-full border-0"
-          title={fullDoc.title}
-        ></iframe>
-      {:else if viewerType === 'preview-pdf'}
-        <iframe
-          src="/api/documents/{fullDoc.id}/preview?token={getAccessToken()}"
-          class="w-full h-full border-0"
-          title={fullDoc.title}
-          onerror={() => {}}
-        ></iframe>
-      {:else if viewerType === 'image'}
-        <div class="flex items-center justify-center h-full p-4">
-          <img
-            src="/api/documents/{fullDoc.id}/file?token={getAccessToken()}"
-            alt={fullDoc.title}
-            class="max-w-full max-h-full object-contain rounded"
+        <div class="p-4 flex flex-col h-full">
+          <div class="mb-2 flex items-center gap-2 shrink-0">
+            <MarkdownStatusBadge mdStatus={fullDoc.md_status} mdExtractionError={fullDoc.md_extraction_error} mdExtractionQuality={fullDoc.md_extraction_quality} />
+            {#if canShowMarkdown}
+              <button onclick={() => (pdfViewMode = 'markdown')}
+                class="px-2 py-1 text-xs rounded border {pdfViewMode === 'markdown' ? 'bg-accent text-white border-accent' : 'text-dim border-default hover:text-accent'}">Markdown</button>
+              <button onclick={() => (pdfViewMode = 'pdf')}
+                class="px-2 py-1 text-xs rounded border {pdfViewMode === 'pdf' ? 'bg-accent text-white border-accent' : 'text-dim border-default hover:text-accent'}">PDF 원본</button>
+            {/if}
+          </div>
+          {#if pdfViewMode === 'markdown' && canShowMarkdown}
+            <div class="flex-1 overflow-auto">
+              <MarkdownDoc
+                documentId={fullDoc.id}
+                mdContent={fullDoc.md_content}
+                mdFrontmatter={fullDoc.md_frontmatter}
+                mdStatus={fullDoc.md_status}
+                mdExtractionError={fullDoc.md_extraction_error}
+                mdExtractionQuality={fullDoc.md_extraction_quality}
+                extractedText={fullDoc.extracted_text}
+                class={PROSE}
+              />
+            </div>
+          {:else}
+            <iframe src="/api/documents/{fullDoc.id}/file?token={getAccessToken()}" class="flex-1 w-full border-0 rounded" title={fullDoc.title}></iframe>
+          {/if}
+        </div>
+      {:else if viewerType === 'hwp-markdown'}
+        <div class="p-4">
+          <MarkdownDoc
+            documentId={fullDoc.id}
+            mdContent={fullDoc.md_content}
+            mdFrontmatter={fullDoc.md_frontmatter}
+            mdStatus={fullDoc.md_status}
+            mdExtractionError={fullDoc.md_extraction_error}
+            mdExtractionQuality={fullDoc.md_extraction_quality}
+            extractedText={fullDoc.extracted_text}
+            class={PROSE}
           />
         </div>
+      {:else if viewerType === 'preview-pdf'}
+        <iframe src="/api/documents/{fullDoc.id}/preview?token={getAccessToken()}" class="w-full h-full border-0" title={fullDoc.title} onerror={() => {}}></iframe>
+      {:else if viewerType === 'image'}
+        <div class="flex items-center justify-center h-full p-4">
+          <img src="/api/documents/{fullDoc.id}/file?token={getAccessToken()}" alt={fullDoc.title} class="max-w-full max-h-full object-contain rounded" />
+        </div>
       {:else if viewerType === 'text'}
-        <div class="p-4">
-          <pre class="text-sm text-text whitespace-pre-wrap font-mono">{fullDoc.extracted_text || '텍스트 없음'}</pre>
+        <div class="p-4"><pre class="text-sm text-text whitespace-pre-wrap font-mono">{fullDoc.extracted_text || '텍스트 없음'}</pre></div>
+      {:else if viewerType === 'synology'}
+        <div class="flex flex-col items-center justify-center h-full gap-3">
+          <p class="text-sm text-dim">Synology Office 문서 — 외부 편집기에서 열어야 합니다.</p>
+          <a href={fullDoc.edit_url || 'https://link.hyungi.net'} target="_blank" rel="noopener"
+            class="flex items-center gap-1 px-3 py-1.5 text-sm bg-accent text-white rounded-lg hover:bg-accent-hover">
+            <ExternalLink size={14} /> 새 창에서 열기
+          </a>
         </div>
       {:else if viewerType === 'cad'}
         <div class="flex flex-col items-center justify-center h-full gap-3">
           <p class="text-sm text-dim">CAD 미리보기 (향후 지원 예정)</p>
-          <a
-            href="https://web.autocad.com"
-            target="_blank"
-            class="px-3 py-1.5 text-sm bg-accent text-white rounded hover:bg-accent-hover"
-          >AutoCAD Web에서 열기</a>
+          <a href="https://web.autocad.com" target="_blank" rel="noopener" class="px-3 py-1.5 text-sm bg-accent text-white rounded hover:bg-accent-hover">AutoCAD Web에서 열기</a>
         </div>
       {:else if viewerType === 'article'}
-        <!-- 뉴스 전용 뷰어 -->
         <div class="p-5 max-w-3xl mx-auto">
-          <h1 class="text-lg font-bold mb-2">{fullDoc.title}</h1>
+          <h1 class="text-lg font-bold mb-2 text-text">{fullDoc.title}</h1>
           <div class="flex items-center gap-2 mb-4 text-xs text-dim">
             {#if fullDoc.ai_tags?.length}
               {#each fullDoc.ai_tags.filter(t => t.startsWith('News/')) as tag}
-                <span class="px-1.5 py-0.5 rounded bg-blue-900/30 text-blue-400">{tag.replace('News/', '')}</span>
+                <span class="px-1.5 py-0.5 rounded bg-accent/15 text-accent-hover">{tag.replace('News/', '')}</span>
               {/each}
             {/if}
             <span>{new Date(fullDoc.created_at).toLocaleDateString('ko-KR', { year: 'numeric', month: 'short', day: 'numeric', hour: '2-digit', minute: '2-digit' })}</span>
           </div>
-          <div class="markdown-body mb-6">
-            {@html renderMd(fullDoc.extracted_text || '')}
-          </div>
-          <div class="flex items-center gap-3 pt-4 border-t border-default">
-            {#if fullDoc.edit_url}
-              <a
-                href={fullDoc.edit_url}
-                target="_blank"
-                rel="noopener noreferrer"
-                class="flex items-center gap-1 px-3 py-1.5 text-sm bg-accent text-white rounded-lg hover:bg-accent-hover"
-              >
+          <MarkdownDoc
+            documentId={fullDoc.id}
+            mdContent={fullDoc.md_content}
+            mdStatus={fullDoc.md_status}
+            mdExtractionError={fullDoc.md_extraction_error}
+            mdExtractionQuality={fullDoc.md_extraction_quality}
+            extractedText={fullDoc.extracted_text}
+            class="{PROSE} mb-6"
+          />
+          {#if fullDoc.edit_url}
+            <div class="flex items-center gap-3 pt-4 border-t border-default">
+              <a href={fullDoc.edit_url} target="_blank" rel="noopener noreferrer"
+                class="flex items-center gap-1 px-3 py-1.5 text-sm bg-accent text-white rounded-lg hover:bg-accent-hover">
                 <ExternalLink size={14} /> 원문 보기
               </a>
-            {/if}
-          </div>
+            </div>
+          {/if}
         </div>
       {:else}
-        <div class="flex items-center justify-center h-full">
-          <p class="text-sm text-dim">미리보기를 지원하지 않는 형식입니다 ({fullDoc.file_format})</p>
-        </div>
+        <div class="flex items-center justify-center h-full"><p class="text-sm text-dim">미리보기를 지원하지 않는 형식입니다 ({fullDoc.file_format})</p></div>
       {/if}
     {/if}
   </div>

frontend/src/lib/utils/viewerType.ts

@@ -0,0 +1,46 @@
+// 뷰어 타입 분류 단일 source — 상세페이지(/documents/[id])와 3-pane 중앙 리더
+// (DocumentViewer)가 공유한다. 두 곳이 각자 getViewerType 을 두면 csv/hwp/office 분기가
+// drift 하므로(이원화 재발) 여기 하나로 수렴한다.
+//
+// ⚠ 소비 컴포넌트는 이 함수가 낼 수 있는 모든 ViewerType 에 render 분기가 있어야 한다.
+//   (분류 통합 ≠ render 통합 — 양쪽 컴포넌트의 {#if viewerType===...} 에 누락 없는지 확인.)
+
+export type ViewerType =
+  | 'article'
+  | 'markdown'
+  | 'hwp-markdown'
+  | 'pdf'
+  | 'preview-pdf'
+  | 'image'
+  | 'text'
+  | 'synology'
+  | 'cad'
+  | 'unsupported';
+
+const MARKDOWN = new Set(['md', 'txt']);
+// csv/json/xml/html 은 markdown 으로 렌더하면 콤마/행이 한 문단으로 뭉친다 → <pre> 로 원형 보존.
+const TEXT = new Set(['csv', 'json', 'xml', 'html']);
+const HWP = new Set(['hwp', 'hwpx']);
+// LibreOffice headless → PDF preview (/preview) 로 인앱 표시.
+const OFFICE_PREVIEW = new Set(['docx', 'xlsx', 'pptx', 'odt', 'ods', 'odp']);
+// Synology Office 네이티브 — 인앱 변환 부적합, 외부 편집기로.
+const SYNOLOGY = new Set(['odoc', 'osheet']);
+const IMAGE = new Set(['jpg', 'jpeg', 'png', 'gif', 'bmp', 'tiff']);
+const CAD = new Set(['dwg', 'dxf']);
+
+export function getViewerType(
+  format: string | null | undefined,
+  sourceChannel?: string | null,
+): ViewerType {
+  if (sourceChannel === 'news') return 'article';
+  const f = (format ?? '').toLowerCase();
+  if (MARKDOWN.has(f)) return 'markdown';
+  if (f === 'pdf') return 'pdf';
+  if (HWP.has(f)) return 'hwp-markdown';
+  if (OFFICE_PREVIEW.has(f)) return 'preview-pdf';
+  if (SYNOLOGY.has(f)) return 'synology';
+  if (IMAGE.has(f)) return 'image';
+  if (TEXT.has(f)) return 'text';
+  if (CAD.has(f)) return 'cad';
+  return 'unsupported';
+}