Integrate YouTube Music OAuth Flow

[zakkiyyat]

Description:
Enable Google OAuth for YouTube Music to fetch user playlists and preferences.

Requirements:

• Implement Google OAuth2 login
• Handle scopes: https://www.googleapis.com/auth/youtube.readonly
• Fetch user profile and playlist data
• Store tokens and YouTube channel ID in user table

Acceptance Criteria:

• Login and data pull work
• Tokens stored in DB
• User is created or updated

[chemicalcommando]

can i tackle this, return contributor.