[fix](trx-frontend-http): load sat.js with digital-modes plugins

sat.js was only in the 'map' plugin group but the SAT subtab lives
under digital-modes. History/Predictions buttons had no click handlers
until the map tab was visited. The loaded Set prevents double-loading.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Signed-off-by: Stan Grams <sjg@haxx.space>

src/trx-client/trx-frontend/trx-frontend-http/assets/web/index.html

@@ -1561,7 +1561,7 @@
 // Lazy plugin loader: loads plugin scripts when their tab/feature is first activated
 (function() {
   var pluginScripts = {
-    'digital-modes': ['/ft8.js', '/ft4.js', '/ft2.js', '/wspr.js', '/cw.js', '/background-decode.js'],
+    'digital-modes': ['/ft8.js', '/ft4.js', '/ft2.js', '/wspr.js', '/cw.js', '/background-decode.js', '/sat.js'],
     'map': ['/map-core.js', '/leaflet-ais-tracksymbol.js', '/ais.js', '/vdes.js', '/aprs.js', '/hf-aprs.js', '/sat.js', '/sat-scheduler.js'],
     'statistics': ['/map-core.js'],
     'bookmarks': ['/bookmarks.js'],