feat: add superderive stepwise derivation figures

A third sibling toolkit: rewrite steps, justification rails,
cancel/substitute highlights, and lint-on-warning builds.

tests/lint-invalid/formula-order.tex

@@ -0,0 +1,7 @@
+\usepackage[en]{superderive}
+\begin{document}\begin{tikzpicture}
+\sdtopformula{F}{$x$}
+\sdrow{R1}
+  \sdbox{a}{x}
+\sdrowend
+\end{tikzpicture}\end{document}

tests/lint-invalid/hue-budget.tex

@@ -0,0 +1,15 @@
+\usepackage[en]{superderive}
+\sdsetrole{a}{sdTeal}
+\sdsetrole{b}{sdOrange}
+\sdsetrole{c}{sdCoral}
+\sdsetrole{d}{sdViolet}
+\sdsetrole{e}{sdInk}
+\begin{document}\begin{tikzpicture}
+\sdrow{R1}
+  \sdbox[role=a]{a}{1}
+  \sdbox[role=b]{b}{2}
+  \sdbox[role=c]{c}{3}
+  \sdbox[role=d]{d}{4}
+  \sdbox[role=e]{e}{5}
+\sdrowend
+\end{tikzpicture}\end{document}

tests/lint-invalid/raw-tikz.tex

@@ -0,0 +1,7 @@
+\usepackage[en]{superderive}
+\begin{document}\begin{tikzpicture}
+\sdrow{R1}
+  \sdbox{a}{x}
+  \draw (0,0) -- (1,0);
+\sdrowend
+\end{tikzpicture}\end{document}

tests/lint-invalid/two-contrast.tex

@@ -0,0 +1,7 @@
+\usepackage[en]{superderive}
+\begin{document}\begin{tikzpicture}
+\sdrow{R1}
+  \sdcol{c1}{a}{b}
+  \sdcol{c2}{c}{d}
+\sdrowend
+\end{tikzpicture}\end{document}

tests/smoke.tex

@@ -0,0 +1,15 @@
+\documentclass[border=10pt]{standalone}
+\usepackage[en]{superderive}
+\begin{document}
+\begin{tikzpicture}
+\sdstage{S}{smoke}
+\sdrow{R1}
+  \sdbox{a}{x}
+  \sdsubst{b}{x}{y}
+  \sdcancel{c}{z}
+\sdrowend
+\sdbbox{all}
+\sdtopformula{F}{$x\to y$}
+\sdmeaningbox{mb}{80mm}{all}{idea}{rewrite}{caveat}
+\end{tikzpicture}
+\end{document}