[fix](trx-frontend-http): fix bookmark markers invisible on spectrum

let-declared bmList is not a window property, so window.bmList in
app.js always returned undefined. Change to var so it lands on window;
read it via typeof guard in app.js to stay safe if bookmarks.js is absent.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Signed-off-by: Stan Grams <sjg@haxx.space>

src/trx-client/trx-frontend/trx-frontend-http/assets/web/app.js

@@ -4268,8 +4268,9 @@ function drawSpectrum(data) {
   }
 
   // ── Bookmark frequency markers ─────────────────────────────────────────────
-  const visBookmarks = Array.isArray(window.bmList)
-    ? window.bmList.filter((bm) => bm.freq_hz >= range.visLoHz && bm.freq_hz <= range.visHiHz)
+  const _bmListRef = typeof bmList !== "undefined" ? bmList : null;
+  const visBookmarks = Array.isArray(_bmListRef)
+    ? _bmListRef.filter((bm) => bm.freq_hz >= range.visLoHz && bm.freq_hz <= range.visHiHz)
     : [];
   if (visBookmarks.length > 0) {
     ctx.save();
@@ -4317,8 +4318,9 @@ function updateBookmarkAxis(range) {
   const freqAxisEl = document.getElementById("spectrum-freq-axis");
   if (!axisEl) return;
 
-  const visBookmarks = Array.isArray(window.bmList)
-    ? window.bmList.filter((bm) => bm.freq_hz >= range.visLoHz && bm.freq_hz <= range.visHiHz)
+  const _bmRef = typeof bmList !== "undefined" ? bmList : null;
+  const visBookmarks = Array.isArray(_bmRef)
+    ? _bmRef.filter((bm) => bm.freq_hz >= range.visLoHz && bm.freq_hz <= range.visHiHz)
     : [];
 
   const hasVisible = visBookmarks.length > 0;

src/trx-client/trx-frontend/trx-frontend-http/assets/web/plugins/bookmarks.js

@@ -1,6 +1,6 @@
 // --- Bookmarks Tab ---
 
-let bmList = [];
+var bmList = [];
 let bmEditId = null;
 
 function bmFmtFreq(hz) {