Content stub — prose, diagrams, and Lean 4 exercises to be written.
This week covers: The arena: contact structure ξ on M, Legendrian submanifolds, contact forms. Why contact geometry, not Riemannian.
Primary chapter references from book/: hub.html, chPI-recurrence.html
-- dm³ 101 · Week 01 · Lean 4 Lab -- Operator: G (Operator Chain) -- TODO: fill in theorems and exercises -- stub example : True := trivial