fix: prevent double-wrapping of download URLs in MarkdownRenderer (#529)

Co-authored-by: Hango Liang <Hango>
Co-authored-by: Claude Opus 4.7 <noreply@anthropic.com>

packages/client/src/api/hermes/download.ts

@@ -6,6 +6,19 @@ import { getApiKey, getBaseUrlValue } from '../client'
  */
 export function getDownloadUrl(filePath: string, fileName?: string): string {
   const base = getBaseUrlValue()
+
+  // Guard: if filePath is already a full download URL, extract the real path
+  // to prevent double-wrapping (/api/hermes/download?path=/api/hermes/download?path=...)
+  if (filePath.startsWith('/api/hermes/download?')) {
+    try {
+      const parsed = new URL(filePath, 'http://localhost')
+      const realPath = parsed.searchParams.get('path')
+      if (realPath) filePath = realPath
+    } catch {
+      // fall through with original filePath
+    }
+  }
+
   // Decode the path first in case it's already encoded (e.g., from AI responses)
   // URLSearchParams will encode it again, so we need to start with decoded text
   const decodedPath = decodeURIComponent(filePath)