docs(console): note single-form assumption near activeBinding

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

l4d2web/l4d2web/static/js/console-autocomplete.js

@@ -18,6 +18,9 @@ const MAX_RENDERED = 8;
 // Module-scoped state.
 let vocabPromise = null;
 let vocab = null;
+// activeBinding assumes a single dropdown open at a time. Today the
+// project has one console form per page; multi-form support would
+// need per-form open-state tracking (e.g. a Set) here.
 let activeBinding = null;
 
 function loadVocab() {