fix: Pass bias-T setting to ADS-B and AIS dashboards

The bias-T checkbox on the main dashboard was not being passed to the
ADS-B and AIS tracking start requests. Added getBiasTEnabled() helper
to each dashboard that reads from shared localStorage, and updated all
start request bodies to include bias_t parameter.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

templates/adsb_dashboard.html

@@ -316,6 +316,13 @@
     </main>
 
     <script>
+        // ============================================
+        // BIAS-T HELPER (reads from main dashboard localStorage)
+        // ============================================
+        function getBiasTEnabled() {
+            return localStorage.getItem('biasTEnabled') === 'true';
+        }
+
         // ============================================
         // STATE
         // ============================================
@@ -2424,7 +2431,8 @@ sudo make install</code>
                 const adsbDevice = parseInt(document.getElementById('adsbDeviceSelect').value) || 0;
 
                 const requestBody = {
-                    device: adsbDevice
+                    device: adsbDevice,
+                    bias_t: getBiasTEnabled()
                 };
                 if (remoteConfig) {
                     requestBody.remote_sbs_host = remoteConfig.host;
@@ -2605,7 +2613,7 @@ sudo make install</code>
                 const startResponse = await fetch('/adsb/start', {
                     method: 'POST',
                     headers: { 'Content-Type': 'application/json' },
-                    body: JSON.stringify({ device: device })
+                    body: JSON.stringify({ device: device, bias_t: getBiasTEnabled() })
                 });
 
                 const result = await startResponse.json();