fix: login, session expiration, concurrent sessions

[projectakshith]

Fixed login and session expiration issues including concurrent session page, and better session stability

Cookie Management:

• Added a manual Cookie Jar system (extractCookies and getCookieStr).
• The login now follows the full redirect chain to the oauthorize_uri using fasthttp.DoRedirects.

For concurrent sessions:

• Added a detection layer that identifies the Zoho termination page.
• Used goquery to parse the HTML, extract the necessary security tokens, and automatically POST the termination request.