feat: add v3 charts with animations and premium effects

- chart-growth-v3.svg: animated gradient fill, pulsing data points, shimmer
- chart-cost-v3.svg: bar animations, shine effects, glowing savings badge
- chart-features-v3.svg: row animations, checkmarks, metric cards
- social-v3.svg: full banner with routing flow, animated arrows, glow effects

Features: CSS keyframes, SMIL animations, gradient fills, glow filters, grid patterns

Author: Subhajit das