Fixing the figure references

[rogelj]

This fixed issue #131

This patch fixes broken figure references (\ref, \autoref) in figure, figure*, and marginfigure under recent TeX Live releases (notably with amsmath + hyperref).

Problem

tufte-common.def defers caption and label processing by storing \caption and \label and applying them later inside a boxed minipage.

At label application time, the figure counter has not been ref-stepped, so:

• \label does not capture the figure counter
• hyperref sees no valid anchor
• References resolve to ??, empty links, or section numbers

This regression is exposed by newer amsmath versions but reflects a long-standing ordering issue.

Fix: When applying the stored label, explicitly ref-step the figure counter:

\addtocounter{figure}{-1}
\refstepcounter{figure}
\@tufte@orig@label{<label>}

This:

• restores the correct figure number
• creates a proper hyperlink anchor
• preserves existing numbering and layout

Standard LaTeX captions use \refstepcounter so that labels placed after captions reliably bind to the float.
This patch restores that invariant in Tufte’s delayed-caption architecture.

Result

• \label after \caption works as documented
• \ref, \autoref, and hyperref links resolve correctly
• Compatible with current TeX Live (2025+) and earlier releases