Second P1 growth engine: compare two profiles, gate full tips behind
deep-access mock payment, and list personal archives on /profile.
Co-authored-by: Cursor <cursoragent@cursor.com>
Establish product language contract, user journey with dual growth engines,
ERD/OpenAPI/Go boundaries, and H5 routes (/profile, /portrait, /relation,
/membership) before P1 implementation.
Co-authored-by: Cursor <cursoragent@cursor.com>