⚗️ Reaction viewer

A reaction re-weaves Fibers: Knits (bonds) break and re-form under conditions (temperature, pressure, catalyst — see #109). Balanced equations drawn from molgang's molecule vocabulary. Building block for reactions as a new knit type on the fabric.

molgang-native, dependency-free structural equations (CPK colours). Ties to the molecule viewer. Real thermochemistry / kinetics and reaction modelling as a knit type are on the #109 / #214 roadmap.