paper(platform): widen SIP/CUBE subfigures, drop height cap

- subfig widths 0.46 -> 0.495 textwidth so the \hfill gap between
  (a) SIP and (b) CUBE shrinks to ~2% textwidth instead of ~8%.
- Removed the height=0.85\linewidth cap on both subfigures; with the
  cap, the (roughly 1:1) SIP and CUBE diagrams were being scaled
  down to 85% even when the column had room. Let them render at
  their natural aspect ratio.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

docs/report/1H-codesign-paper/sections/02-platform.tex

@@ -73,15 +73,15 @@ attention (\S\ref{sec:gqa}).
 
 \begin{figure*}[t]
 \centering
-\begin{subfigure}[t]{0.46\textwidth}
+\begin{subfigure}[b]{0.495\textwidth}
   \centering
-  \includegraphics[width=\linewidth,height=0.85\linewidth,keepaspectratio]{sip_architecture.pdf}
+  \includegraphics[width=\linewidth]{sip_architecture.pdf}
   \caption{SIP level: $4{\times}4$ CUBE mesh + IO chiplet.}
   \label{fig:sip-arch}
 \end{subfigure}\hfill
-\begin{subfigure}[t]{0.46\textwidth}
+\begin{subfigure}[b]{0.495\textwidth}
   \centering
-  \includegraphics[width=\linewidth,height=0.85\linewidth,keepaspectratio]{cube_architecture.pdf}
+  \includegraphics[width=\linewidth]{cube_architecture.pdf}
   \caption{CUBE level (zoom-in of one CUBE in (a)): 8 PEs, HBM
   channels, M\_CPU, SRAM, NoC router mesh, UCIe links.}
   \label{fig:cube-arch}