feat: major quality & diversity overhaul

fix: larger CV fonts for readability, 4-7 bullet points per role, force experience extraction from raw text, ban summary text in education

fix: RGBColor is a tuple subclass, use indexing not .red/.green/.blue attrs

fix: restore missing generate_cv_pdf function definition

feat: CV diversity profiles, Gemma provider, transferable skills, paste persistence, improved fallback

Initial commit: Joblin platform