fix(docs-codegen): escape backslashes before pipes in controls-table cells

Escaping only the pipe let an authored backslash combine with the inserted
escape (or a following character) into an unintended sequence — CodeQL
js/incomplete-string-escaping. Backslashes are now escaped first, so authored
text round-trips faithfully into the markdown table.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Author: jbernard077

scripts/generate-catalog-pages.ts

@@ -792,9 +792,13 @@ interface ItemControl {
   drives: string;
 }
 
-/** Pipe characters break table cells; everything user-authored passes through here. */
+/**
+ * Pipes break table cells; everything user-authored passes through here.
+ * Backslashes are escaped first so an authored `\` can never combine with the
+ * inserted `\|` escapes (or a following character) into an unintended sequence.
+ */
 function tableCell(value: string): string {
-  return value.replace(/\|/g, "\\|");
+  return value.replace(/\\/g, "\\\\").replace(/\|/g, "\\|");
 }
 
 /** The allowed inputs for one control, written the way a reader has to type them. */