fix: add contentType key to /api/registry/file/... response

Author: shuuji3

server/api/registry/file/[...pkg].get.ts

@@ -50,7 +50,7 @@ async function fetchFileContent(
   packageName: string,
   version: string,
   filePath: string,
-): Promise<string> {
+): Promise<{ content: string; contentType: string | null }> {
   const url = `https://cdn.jsdelivr.net/npm/${packageName}@${version}/${filePath}`
   const response = await fetch(url)
 
@@ -64,6 +64,8 @@ async function fetchFileContent(
     })
   }
 
+  const contentType = response.headers.get('content-type')
+
   // Check content-length header if available
   const contentLength = response.headers.get('content-length')
   if (contentLength && parseInt(contentLength, 10) > MAX_FILE_SIZE) {
@@ -83,7 +85,7 @@ async function fetchFileContent(
     })
   }
 
-  return content
+  return { content, contentType }
 }
 
 /**
@@ -123,7 +125,7 @@ export default defineCachedEventHandler(
         filePath: rawFilePath,
       })
 
-      const content = await fetchFileContent(packageName, version, filePath)
+      const { content, contentType } = await fetchFileContent(packageName, version, filePath)
       const language = getLanguageFromPath(filePath)
 
       // For JS/TS files, resolve dependency versions and relative imports for linking
@@ -185,6 +187,7 @@ export default defineCachedEventHandler(
         version,
         path: filePath,
         language,
+        contentType,
         content,
         html,
         lines: content.split('\n').length,