fix(blob): use TextDecoder for proper UTF-8 decoding

- atob() returns Latin-1 binary string, not UTF-8
- Chinese characters decoded incorrectly causing mojibake
- Use TextDecoder("utf-8") with Uint8Array for correct handling

src/components/repository/file-browser.tsx

@@ -115,9 +115,11 @@ export const FileBrowser = ({ branch, initialPath = "" }: FileBrowserProps) => {
       });
       const data = resp.data?.data;
       if (!data) return null;
-      // Content is base64 encoded
+      // Content is base64 encoded, use TextDecoder for proper UTF-8 handling
       try {
-        return atob(data.content);
+        const binary = atob(data.content);
+        const bytes = Uint8Array.from(binary, c => c.charCodeAt(0));
+        return new TextDecoder("utf-8", { fatal: false }).decode(bytes);
       } catch {
         return data.content;
       }