Fix agent/local mode state sync and process cleanup

Agent fixes:
- Fix stop not killing secondary processes (pager_rtl, aprs_rtl, rtlamr_tcp)
- Modes using piped processes now properly terminate all child processes

UI state sync fixes:
- Add syncLocalModeStates() to check local status when switching to local
- Fix switchMode() to re-sync with agent/local when changing mode tabs
- Only stop local modes when actually in local mode
- UI now correctly reflects running state when switching agents or modes

templates/index.html

@@ -2092,16 +2092,28 @@
 
         // Mode switching
         function switchMode(mode) {
-            // Stop any running scans when switching modes
-            if (isRunning) stopDecoding();
-            if (isSensorRunning) stopSensorDecoding();
-            if (isWifiRunning) stopWifiScan();
-            if (isBtRunning) stopBtScan();
-            if (isAprsRunning) stopAprs();
-            if (isTscmRunning) stopTscmSweep();
+            // Only stop local scans if in local mode (not agent mode)
+            const isAgentMode = typeof currentAgent !== 'undefined' && currentAgent !== 'local';
+            if (!isAgentMode) {
+                if (isRunning) stopDecoding();
+                if (isSensorRunning) stopSensorDecoding();
+                if (isWifiRunning) stopWifiScan();
+                if (isBtRunning) stopBtScan();
+                if (isAprsRunning) stopAprs();
+                if (isTscmRunning) stopTscmSweep();
+            }
 
             currentMode = mode;
 
+            // Sync mode state with current agent/local after switching
+            if (isAgentMode && typeof syncAgentModeStates === 'function') {
+                // Re-sync with agent to update this mode's UI state
+                syncAgentModeStates(currentAgent);
+            } else if (!isAgentMode && typeof syncLocalModeStates === 'function') {
+                // Sync with local status
+                syncLocalModeStates();
+            }
+
             // Close dropdowns and update active state
             closeAllDropdowns();
             updateDropdownActiveState();