fix: [문서스냅샷] UpsertRequest rendered_html 검증 추가 및 upsert() 전달 누락 수정

- UpsertRequest에 rendered_html nullable string 검증 추가
- DocumentService upsert()에서 create/update 시 rendered_html 전달

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

app/Http/Requests/Document/UpsertRequest.php

@@ -30,6 +30,9 @@ public function rules(): array
             'data.*.field_key' => 'required_with:data|string|max:100',
             'data.*.field_value' => 'nullable|string',
 
+            // HTML 스냅샷
+            'rendered_html' => 'nullable|string',
+
             // 첨부파일
             'attachments' => 'nullable|array',
             'attachments.*.file_id' => 'required_with:attachments|integer|exists:files,id',

app/Services/DocumentService.php

@@ -857,24 +857,32 @@ public function upsert(array $data): Document
 
             if ($existingDocument) {
                 // UPDATE: 기존 update 로직 재사용
-                return $this->update($existingDocument->id, [
+                $updatePayload = [
                     'title' => $data['title'] ?? $existingDocument->title,
                     'linkable_type' => 'item',
                     'linkable_id' => $itemId,
                     'data' => $data['data'] ?? [],
                     'attachments' => $data['attachments'] ?? [],
-                ]);
+                ];
+                if (isset($data['rendered_html'])) {
+                    $updatePayload['rendered_html'] = $data['rendered_html'];
+                }
+                return $this->update($existingDocument->id, $updatePayload);
             }
 
             // CREATE: 기존 create 로직 재사용
-            return $this->create([
+            $createPayload = [
                 'template_id' => $templateId,
                 'title' => $data['title'] ?? '',
                 'linkable_type' => 'item',
                 'linkable_id' => $itemId,
                 'data' => $data['data'] ?? [],
                 'attachments' => $data['attachments'] ?? [],
-            ]);
+            ];
+            if (isset($data['rendered_html'])) {
+                $createPayload['rendered_html'] = $data['rendered_html'];
+            }
+            return $this->create($createPayload);
         });
     }