review: clarify newNode isLeaf comment wording (Copilot)

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: vishr

router.go

@@ -708,9 +708,9 @@ func newNode(
 		methods:        mh,
 		paramChild:     paramChildren,
 		anyChild:       anyChildren,
-		// len() (not == nil) so an empty-but-non-nil sc — e.g. a slice a prior
-		// Remove spliced down to length 0 — is still treated as no children,
-		// matching refreshLeaf.
+		// len() (not == nil) so an empty-but-non-nil sc — e.g. a slice from a
+		// prior Remove that was spliced down to length 0 — is still treated as
+		// no children, matching refreshLeaf.
 		isLeaf:    len(sc) == 0 && paramChildren == nil && anyChildren == nil,
 		isHandler: mh.isHandler(),
 	}