fix(tooling): prefix unused regex-callback arg to satisfy no-unused-vars

The `![alt](*.svg)` replace callback in rewriteDiagramEmbeds binds the
full-match argument as `whole` but only uses `alt`, tripping ESLint
`no-unused-vars` (the shakacode config allows unused args only when
`_`-prefixed). Rename to `_whole`. Pure no-op for generator output —
llms-full*.txt are byte-identical after regeneration.

Flagged by CodeRabbit review. The repo lint job is path-gated and was
skipped for this docs/tooling PR, so the violation would otherwise surface
on a full-CI or main run.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Author: justin808

script/generate-llms-full.mjs

@@ -286,7 +286,7 @@ function rewriteDiagramEmbeds(text) {
       return rewritten === img ? whole : rewritten;
     })
     .replace(/<img\b[^>]*>/gi, (img) => rewriteImgTag(img))
-    .replace(/!\[([^\]]*)\]\([^)\s]*\.svg\)/gi, (whole, alt) => diagramMarker(alt));
+    .replace(/!\[([^\]]*)\]\([^)\s]*\.svg\)/gi, (_whole, alt) => diagramMarker(alt));
 }
 
 // Apply rewriteDiagramEmbeds to a doc body while leaving fenced code blocks