Update footer: consolidate tool links into single arch-docs link

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: greynewell

generate-index.go

@@ -415,7 +415,7 @@ a:focus-visible { outline: 2px solid var(--accent-light); outline-offset: 2px; b
 
   <footer class="site-footer">
     <div class="container">
-      <p>Generated by <a href="https://github.com/supermodeltools/arch-docs">arch-docs</a> with <a href="https://supermodeltools.com">supermodeltools</a>, <a href="https://github.com/supermodeltools/graph2md">graph2md</a>, and <a href="https://github.com/greynewell/pssg">pssg</a></p>
+      <p>Generated with <a href="https://github.com/supermodeltools/arch-docs">arch-docs</a> by <a href="https://supermodeltools.com">supermodeltools</a></p>
     </div>
   </footer>