e80d717aa7
Replace ~20 ASCII diagrams across §1–§10 with polished Unicode art: - Proper axes: ╰──→ ▲ ╌ with tick marks and labels - Curves: ╭─╮ ╰─╯ ╲ ╱ for smooth paths and bells - Steps: ─── ┐ └ for Poisson staircase - Fills: ▓ ░ · ◦ ● for density and scatter plots - Tables: ┌┬─┤├┼┘ Unicode box drawing for HMM state machine - Remove duplicate BM fan + GBM diagrams (were repeated verbatim) - Consistent 44-char width, title banners with ┄ separators