[fix](trx-frontend-http): fix TDZ on overviewDrawPending at style init

setStyle() was called at module init time (to restore the saved style
from localStorage) before the let overviewDrawPending declaration, which
caused a ReferenceError: Cannot access 'overviewDrawPending' before
initialization.

Fix: hoist let overviewDrawPending = false to the top of the variable
declarations block, before any top-level code that may call
scheduleOverviewDraw(). Remove the now-duplicate declaration from its
original location.

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

@@ -332,6 +332,7 @@ const headerRigSwitchSelect = document.getElementById("header-rig-switch-select"
 const headerStylePickSelect = document.getElementById("header-style-pick-select");
 let overviewPeakHoldMs = Number(loadSetting("overviewPeakHoldMs", 2000));
 
+let overviewDrawPending = false;
 let lastControl;
 let lastTxEn = null;
 let lastHasTx = true;
@@ -622,7 +623,6 @@ let reconnectTimer = null;
 let overviewSignalSamples = [];
 let overviewSignalTimer = null;
 let overviewWaterfallRows = [];
-let overviewDrawPending = false;
 const HEADER_SIG_WINDOW_MS = 10_000;
 
 function resizeHeaderSignalCanvas() {