[MCP] Implement token-based authentication to bypass Cloudflare captcha

[pranjalagg]

Problem

The current implementation is being blocked by Cloudflare captcha, which prevents users from downloading songs. This is a critical issue that breaks the core functionality of the application.

Proposed Solution

Implement a token-based authentication system that allows users to:

1. Extract a token from spotifydown.com manually (one-time process)
2. Use this token in the application to bypass Cloudflare protection
3. Automatically refresh tokens when they expire

Implementation Details

• Add token configuration to config.py
• Modify spotify_api.py to use token-based requests
• Update main.py to handle token validation
• Add clear documentation for token extraction process
• Implement token refresh mechanism

Benefits

• Bypasses Cloudflare captcha protection
• Maintains existing functionality
• Provides better user experience

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Note: This issue and the associated PR were created using GitHub MCP as a test to demonstrate automated issue tracking and development workflow capabilities.