feat(settings): add Sync Servers toggle (off by default)

- Add syncServers setting (default false) to extension and native host state
- Add "Sync Servers" toggle under Settings → Sync; when disabled, server
  tunnels stay local and are not synced across linked devices
- On push: omit servers from snapshot when syncServers is false
- On apply: keep local servers and nextServerId when syncServers is false
  (incremental and full restore)

extension/dashboard/core/state.js

@@ -14,7 +14,8 @@ const SETTINGS_DEFAULTS = {
   tunnelAutoReconnect: true,
   latencyPingEnabled: false,
   latencyPingIntervalMs: 5000,
-  dashboardRefreshIntervalMs: 2000
+  dashboardRefreshIntervalMs: 2000,
+  syncServers: false
 };
 
 let currentState = null;

extension/dashboard/dashboard.html

@@ -688,6 +688,18 @@
                 <div class="toggle" id="toggleTunnelAutoReconnect" data-setting="tunnelAutoReconnect"></div>
               </div>
             </div>
+
+            <div class="section-heading">Sync</div>
+            <div class="setting-row">
+              <div class="setting-info">
+                <div class="setting-label">Sync Servers</div>
+                <div class="setting-desc">When enabled, server tunnels are synced across linked devices. When disabled (default), server tunnels stay local to this device.</div>
+              </div>
+              <div class="setting-control">
+                <div class="toggle" id="toggleSyncServers" data-setting="syncServers"></div>
+              </div>
+            </div>
+
             <div class="setting-row">
               <div class="setting-info">
                 <div class="setting-label">Debug Mode</div>

extension/dashboard/pages/settings.js

@@ -26,6 +26,7 @@ function updateSettingsUI() {
   $('toggleNotify')?.classList.toggle('active', settings.notifyOnDisconnect === true);
   $('toggleNotifyTunnelError')?.classList.toggle('active', settings.notifyOnTunnelError !== false);
   $('toggleTunnelAutoReconnect')?.classList.toggle('active', settings.tunnelAutoReconnect === true);
+  $('toggleSyncServers')?.classList.toggle('active', settings.syncServers === true);
   $('toggleDebug')?.classList.toggle('active', settings.debug === true);
   $('toggleDisableFileUrls')?.classList.toggle('active', settings.disableOnFileUrls === true);
   $('toggleTheme')?.classList.toggle('active', document.documentElement.getAttribute('data-theme') === 'light');
@@ -48,6 +49,7 @@ function saveSettings() {
   settings.notifyOnDisconnect = $('toggleNotify')?.classList.contains('active') ?? SETTINGS_DEFAULTS.notifyOnDisconnect;
   settings.notifyOnTunnelError = $('toggleNotifyTunnelError')?.classList.contains('active') ?? SETTINGS_DEFAULTS.notifyOnTunnelError;
   settings.tunnelAutoReconnect = $('toggleTunnelAutoReconnect')?.classList.contains('active') ?? SETTINGS_DEFAULTS.tunnelAutoReconnect;
+  settings.syncServers = $('toggleSyncServers')?.classList.contains('active') ?? SETTINGS_DEFAULTS.syncServers;
   settings.debug = $('toggleDebug')?.classList.contains('active') ?? SETTINGS_DEFAULTS.debug;
   settings.disableOnFileUrls = $('toggleDisableFileUrls')?.classList.contains('active') ?? SETTINGS_DEFAULTS.disableOnFileUrls;
   settings.latencyPingEnabled = $('toggleLatencyPing')?.classList.contains('active') ?? SETTINGS_DEFAULTS.latencyPingEnabled;

native-host/holesail-manager/settings.js

@@ -47,6 +47,7 @@ function updateSettings(patch) {
   if (typeof patch.dashboardRefreshIntervalMs === 'number' && patch.dashboardRefreshIntervalMs >= 0 && [0, 2000, 5000, 10000].includes(patch.dashboardRefreshIntervalMs)) {
     currentSettings.dashboardRefreshIntervalMs = patch.dashboardRefreshIntervalMs;
   }
+  if (typeof patch.syncServers === 'boolean') currentSettings.syncServers = patch.syncServers;
   if (_saveState) _saveState();
   return { requiresRestart };
 }

native-host/holesail-manager/state.js

@@ -23,7 +23,8 @@ const SETTINGS_DEFAULTS = {
   tunnelAutoReconnect: true,
   latencyPingEnabled: false,
   latencyPingIntervalMs: 5000,
-  dashboardRefreshIntervalMs: 2000
+  dashboardRefreshIntervalMs: 2000,
+  syncServers: false
 };
 
 const DEBUG = process.env.HOLESAIL_DEBUG === '1' || process.env.HOLESAIL_DEBUG === 'true';

native-host/managers/sync-manager.js

@@ -315,7 +315,9 @@ async function applySyncedStateIncremental(snapshot) {
       if (myId) snapshot.deviceNames[myId] = typeof os.hostname === 'function' ? os.hostname() : 'device';
     }
     const current = getStateSnapshot();
-    const snapServers = Array.isArray(snapshot.servers) ? snapshot.servers : [];
+    const settings = holesailManager.getSettings ? holesailManager.getSettings() : {};
+    const syncServers = settings.syncServers === true;
+    const snapServers = syncServers && Array.isArray(snapshot.servers) ? snapshot.servers : [];
     const snapVhosts = Array.isArray(snapshot.virtualHosts) ? snapshot.virtualHosts : [];
     const snapSvc = Array.isArray(snapshot.serviceTunnels) ? snapshot.serviceTunnels : [];
     const curVhosts = new Map((current.virtualHosts || []).map(v => [String(v.hostname || '').toLowerCase(), v]));
@@ -325,7 +327,8 @@ async function applySyncedStateIncremental(snapshot) {
     const snapServersById = new Map(snapServers.map(s => [s.id, s]));
     const snapSvcById = new Map(snapSvc.map(t => [t.id, t]));
 
-    applySnapshotData(snapshot);
+    const snapshotToApply = syncServers ? snapshot : { ...snapshot, servers: [], nextServerId: current.nextServerId };
+    applySnapshotData(snapshotToApply);
 
     for (const [hostname] of curVhosts) {
       if (!snapVhostsByHost.has(hostname)) {
@@ -378,7 +381,8 @@ async function applySyncedStateIncremental(snapshot) {
 
     const dir = path.dirname(statePath);
     if (!fs.existsSync(dir)) fs.mkdirSync(dir, { recursive: true });
-    fs.writeFileSync(statePath, JSON.stringify(snapshot, null, 2), 'utf8');
+    const toWrite = syncServers ? snapshot : { ...snapshot, servers: current.servers || [], nextServerId: current.nextServerId };
+    fs.writeFileSync(statePath, JSON.stringify(toWrite, null, 2), 'utf8');
   } finally {
     setStateSaveSuppressed(false);
     applyingSync = false;
@@ -399,6 +403,12 @@ async function applySyncedStateFull(snapshot) {
       const myId = shortId(pass.writerKey);
       if (myId) snapshot.deviceNames[myId] = typeof os.hostname === 'function' ? os.hostname() : 'device';
     }
+    const settings = holesailManager.getSettings ? holesailManager.getSettings() : {};
+    if (settings.syncServers !== true) {
+      const current = holesailManager.getStateSnapshot ? holesailManager.getStateSnapshot() : {};
+      snapshot.servers = Array.isArray(current.servers) ? current.servers : [];
+      snapshot.nextServerId = typeof current.nextServerId === 'number' ? current.nextServerId : 0;
+    }
     const dir = path.dirname(statePath);
     if (!fs.existsSync(dir)) fs.mkdirSync(dir, { recursive: true });
     const json = JSON.stringify(snapshot, null, 2);
@@ -430,6 +440,9 @@ function onStateSaved(snapshot) {
   if (applyingSync || !pass) return;
   (async () => {
     try {
+      if (holesailManager && typeof holesailManager.getSettings === 'function' && !holesailManager.getSettings().syncServers) {
+        snapshot.servers = [];
+      }
       const myId = shortId(pass.writerKey);
       if (myId) {
         snapshot.deviceNames = snapshot.deviceNames || {};