chore: add chart of supra competive pricing

paper/src/chapters/04-results.tex

@@ -1,4 +1,10 @@
 \section{Results}
+\begin{figure}[ht]
+    \centering
+    \input{chapters/figures/supra.tex}
+    \caption{Evolution of price distributions over experiment steps. The heatmap illustrates the density of price offerings. This is an early baseline simulation which demonstrates supra-competitive price-setting in deep learning agents such as SAC as can be clearly seen by the high density at the highest available price.}
+    \label{fig:supra_heatmap}
+\end{figure}
 
 \subsection{Behavioral Analysis}