fix: Wire up VDL2 agent mode, fix dashboard layout gap and stats strip sizing

- Add VDL2 to syncModeUI setter map and allModes array in agents.js
  so agent state sync works for VDL2
- Fix dashboard bottom gap by using flex layout on body instead of
  hardcoded calc(100dvh - 160px) height
- Match source stat font-size to other stats (14px) for consistent
  strip sizing
- Add left-sidebars wrapper, VDL2 agent mode support, mutual sidebar
  collapse, and ACARS/VDL2 modeNames in index.html

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

static/js/core/agents.js

@@ -423,7 +423,7 @@ async function syncAgentModeStates(agentId) {
                 });
 
                 // Also check modes that might need to be marked as stopped
-                const allModes = ['sensor', 'pager', 'adsb', 'wifi', 'bluetooth', 'ais', 'dsc', 'acars', 'aprs', 'rtlamr', 'tscm', 'satellite', 'listening_post'];
+                const allModes = ['sensor', 'pager', 'adsb', 'wifi', 'bluetooth', 'ais', 'dsc', 'acars', 'vdl2', 'aprs', 'rtlamr', 'tscm', 'satellite', 'listening_post'];
                 allModes.forEach(mode => {
                     if (!agentRunningModes.includes(mode)) {
                         syncModeUI(mode, false, agentId);
@@ -704,6 +704,7 @@ function syncModeUI(mode, isRunning, agentId = null) {
         'wifi': 'setWiFiRunning',
         'bluetooth': 'setBluetoothRunning',
         'acars': 'setAcarsRunning',
+        'vdl2': 'setVdl2Running',
         'listening_post': 'setListeningPostRunning'
     };
 
@@ -865,12 +866,12 @@ function connectAgentStream(mode, onMessage) {
     }
 
     let streamUrl;
-    if (currentAgent === 'local') {
-        streamUrl = `/${mode}/stream`;
-    } else {
-        // For remote agents, proxy SSE through controller
-        streamUrl = `/controller/agents/${currentAgent}/${mode}/stream`;
-    }
+    if (currentAgent === 'local') {
+        streamUrl = `/${mode}/stream`;
+    } else {
+        // For remote agents, proxy SSE through controller
+        streamUrl = `/controller/agents/${currentAgent}/${mode}/stream`;
+    }
 
     agentEventSource = new EventSource(streamUrl);
 
@@ -878,7 +879,7 @@ function connectAgentStream(mode, onMessage) {
         try {
             const data = JSON.parse(event.data);
 
-            onMessage(data);
+            onMessage(data);
         } catch (e) {
             console.error('Error parsing SSE message:', e);
         }