fix: allow passing single tag in "tags" param

[maxceem]

Issue

1. Connect to Topcoder's MCP using https://github.com/modelcontextprotocol/inspector

2. Add "HTML" tag into "tags":

   

3. Running request returns "Error fetching challenges: Request failed with status code 400"

Fix

Ensure that tags argument always treated by Challenges API as an array by adding [] to the tags param when calling Challenges API:

• instead of tags=AI pass tags[]=AI.

Test

I've tested it locally, now it works for both cases for single tag:

and when passing multiple tags it still working: