fix(sync): persist and cache device names so they are never lost

- state.js: add lastLoadedDeviceNames cache, getDeviceNames(),
  setDeviceNames(); saveStateSync() always merges and writes
  deviceNames so saves never strip them.
- holesail-manager: include deviceNames in saveState() and
  getStateSnapshot(); applySnapshotData() updates cache from
  synced snapshot. buildDefaultState and legacy migration
  include deviceNames: {}.
Prevents hostnames reverting to "Device 1" etc. after saves or sync.

extension/dashboard/dashboard.html

@@ -601,7 +601,7 @@
               <button class="btn btn-secondary" id="btnCopyInvite" style="display:none;">
                 Copy invite
               </button>
-              <div style="display:flex;align-items:center;gap:8px;flex:1;min-width:200px;">
+              <div id="syncLinkDeviceForm" style="display:flex;align-items:center;gap:8px;flex:1;min-width:200px;">
                 <input type="text" id="syncInviteInput" class="input" placeholder="Paste invite from other device" style="flex:1;" />
                 <button class="btn btn-primary" id="btnPairWithInvite">Link device</button>
               </div>
@@ -611,7 +611,7 @@
         </div>
         <div class="card" id="syncLinkedDevicesCard" style="display:none;margin-bottom:16px;">
           <div class="card-body flush">
-            <div class="section-heading" style="padding:0 0 10px 0;">Linked devices</div>
+            <div class="section-heading" style="padding:0 16px 10px 16px;">Linked devices</div>
             <table class="table">
               <thead>
                 <tr>

extension/dashboard/pages/sync.js

@@ -17,15 +17,18 @@ function updateSyncStatus() {
       const btnCopy = $('btnCopyInvite');
       const inviteDisplay = $('syncInviteDisplay');
       if (!text) return;
+      const linkDeviceForm = $('syncLinkDeviceForm');
       if (!response || response.error) {
         if (dot) dot.style.background = 'var(--text4)';
         text.textContent = 'Not linked';
         if (lastSynced) lastSynced.textContent = '';
         if (btnCopy) btnCopy.style.display = 'none';
         if (inviteDisplay) inviteDisplay.style.display = 'none';
+        if (linkDeviceForm) linkDeviceForm.style.display = 'flex';
         return;
       }
       if (response.linked) {
+        if (linkDeviceForm) linkDeviceForm.style.display = 'none';
         if (dot) dot.style.background = 'var(--green)';
         text.textContent = 'Linked';
         if (response.lastSyncedAt) {
@@ -69,6 +72,7 @@ function updateSyncStatus() {
         if (lastSynced) lastSynced.textContent = '';
         if (btnCopy) btnCopy.style.display = 'none';
         if (inviteDisplay) inviteDisplay.style.display = 'none';
+        if (linkDeviceForm) linkDeviceForm.style.display = 'flex';
         const card = $('syncLinkedDevicesCard');
         const tbody = $('syncLinkedDevicesTable');
         if (card) card.style.display = 'none';

native-host/holesail-manager/index.js

@@ -65,7 +65,8 @@ function saveState() {
     virtualHosts: virtualHostsList,
     serviceTunnels: serviceTunnelsList,
     sshConnections: connectionsModule.getSshConnections(),
-    rdpConnections: connectionsModule.getRdpConnections()
+    rdpConnections: connectionsModule.getRdpConnections(),
+    deviceNames: stateModule.getDeviceNames()
   };
   stateModule.saveStateSync(snapshot);
   if (onStateSaved) onStateSaved(snapshot);
@@ -94,7 +95,8 @@ function getStateSnapshot() {
     virtualHosts: virtualHostsList,
     serviceTunnels: serviceTunnelsList,
     sshConnections: connectionsModule.getSshConnections(),
-    rdpConnections: connectionsModule.getRdpConnections()
+    rdpConnections: connectionsModule.getRdpConnections(),
+    deviceNames: stateModule.getDeviceNames()
   };
 }
 
@@ -111,6 +113,7 @@ function applySnapshotData(snapshot) {
   connectionsModule.applyLoaded(ssh, rdp);
   if (typeof snapshot.nextServerId === 'number') serversModule.applyLoaded(snapshot.nextServerId);
   if (typeof snapshot.nextServiceTunnelId === 'number') svcModule.applyLoaded(snapshot.nextServiceTunnelId);
+  if (snapshot.deviceNames != null && typeof snapshot.deviceNames === 'object') stateModule.setDeviceNames(snapshot.deviceNames);
 }
 
 // Inject the shared saveState and emit callbacks into each sub-module

native-host/holesail-manager/state.js

@@ -34,6 +34,8 @@ function debugLog(...args) {
 }
 
 let stateFilePath = null;
+/** In-memory cache of device names (deviceId -> hostname) so they are never lost when saving. */
+let lastLoadedDeviceNames = {};
 
 function setStoragePath(baseDir) {
   if (baseDir && typeof baseDir === 'string') {
@@ -72,13 +74,27 @@ function buildDefaultState() {
     sshConnections: [],
     rdpConnections: [],
     nextServerId: 0,
-    nextServiceTunnelId: 0
+    nextServiceTunnelId: 0,
+    deviceNames: {}
   };
 }
 
+function getDeviceNames() {
+  return { ...lastLoadedDeviceNames };
+}
+
+function setDeviceNames(obj) {
+  if (obj != null && typeof obj === 'object') {
+    lastLoadedDeviceNames = { ...obj };
+  }
+}
+
 function saveStateSync(data) {
   const file = getStatePath();
-  const json = JSON.stringify(data, null, 2);
+  const deviceNames = (data.deviceNames && typeof data.deviceNames === 'object') ? data.deviceNames : lastLoadedDeviceNames;
+  lastLoadedDeviceNames = { ...deviceNames };
+  const toWrite = { ...data, deviceNames: lastLoadedDeviceNames };
+  const json = JSON.stringify(toWrite, null, 2);
   try {
     fs.mkdirSync(path.dirname(file), { recursive: true });
     fs.writeFileSync(file, json, 'utf8');
@@ -97,6 +113,7 @@ function loadState() {
     if (!trimmed) return buildDefaultState();
     const data = JSON.parse(raw);
     if (!data || typeof data !== 'object') return buildDefaultState();
+    lastLoadedDeviceNames = (data.deviceNames && typeof data.deviceNames === 'object') ? { ...data.deviceNames } : {};
     const out = {
       settings: (data.settings && typeof data.settings === 'object') ? { ...SETTINGS_DEFAULTS, ...data.settings } : { ...SETTINGS_DEFAULTS },
       servers: Array.isArray(data.servers) ? data.servers : [],
@@ -106,7 +123,7 @@ function loadState() {
       rdpConnections: Array.isArray(data.rdpConnections) ? data.rdpConnections : [],
       nextServerId: typeof data.nextServerId === 'number' ? data.nextServerId : 0,
       nextServiceTunnelId: typeof data.nextServiceTunnelId === 'number' ? data.nextServiceTunnelId : 0,
-      deviceNames: (data.deviceNames && typeof data.deviceNames === 'object') ? { ...data.deviceNames } : {}
+      deviceNames: { ...lastLoadedDeviceNames }
     };
     debugLog('state loaded path=', file, 'servers=', out.servers.length, 'vhosts=', out.virtualHosts.length);
     if (process.stderr && (out.servers.length || out.virtualHosts.length)) {
@@ -128,6 +145,7 @@ function loadState() {
     if (!trimmed) return buildDefaultState();
     const data = JSON.parse(raw);
     if (process.stderr) process.stderr.write('[holesail-manager] migrating from ' + legacyFile + ' to ' + file + '\n');
+    lastLoadedDeviceNames = {};
     const out = {
       settings: { ...SETTINGS_DEFAULTS },
       servers: Array.isArray(data.servers) ? data.servers : [],
@@ -136,7 +154,8 @@ function loadState() {
       sshConnections: Array.isArray(data.sshConnections) ? data.sshConnections : [],
       rdpConnections: Array.isArray(data.rdpConnections) ? data.rdpConnections : [],
       nextServerId: typeof data.nextServerId === 'number' ? data.nextServerId : 0,
-      nextServiceTunnelId: typeof data.nextServiceTunnelId === 'number' ? data.nextServiceTunnelId : 0
+      nextServiceTunnelId: typeof data.nextServiceTunnelId === 'number' ? data.nextServiceTunnelId : 0,
+      deviceNames: {}
     };
     try { fs.unlinkSync(legacyFile); } catch (_) {}
     if (process.stderr) process.stderr.write('[holesail-manager] migration complete, legacy file removed\n');
@@ -150,4 +169,4 @@ function loadState() {
   return buildDefaultState();
 }
 
-module.exports = { SETTINGS_DEFAULTS, setStoragePath, loadState, saveStateSync, buildDefaultState, ensureStorageDir };
+module.exports = { SETTINGS_DEFAULTS, setStoragePath, loadState, saveStateSync, buildDefaultState, ensureStorageDir, getDeviceNames, setDeviceNames };