Schema math (parts, chapters, sections, activity), seeded with all 100 chapters
(Ch 0-94, appendix A-E), 647 sections, PDF pages, exercise counts and approximate
prereqs. Triggers stamp started_at/completed_at and log status/exercise/note/section
changes; math.apply_progress(jsonb) applies the JSON format bots send. Private by
default via MATH_PRIVATE in #lib/math (owner-only prefix + lock in every tracker list).
Overall + per-part progress, current chapter, prereq hints, quick status buttons,
exercises stepper, notes, optional section ticks, activity log, dependency chart.
Deploy preflight checks the math schema (4 tables, 100 chapters).
