fix tiktok pure-go challenge handling

[Miorszx]

• detect TikTok web challenge pages before parsing
• solve the lightweight challenge in Go and retry the page request with the required cookies
• extend universal-data parsing to support the webapp.video-detail structure and status codes returned by the web page
• return a clearer bot error when TikTok blocks the server IP for a post
• add tests for updated TikTok parsing and challenge-cookie generation
• guard debug file logging so tests can run without an initialized global logger