Support multiple standalone Proxmox hosts with shared credentials

Comma-separated host list logs into every host, merges VM lists tagged
by origin host, and routes SPICE connections to the right one. Also
adds a username format hint (user@realm) on the login form.

src/main.js

@@ -8,7 +8,10 @@ const ProxmoxClient = require('./proxmox');
 
 const store = new Store({ name: 'proxmox-spice-client' });
 let mainWindow;
-let client; // ProxmoxClient instance (persists across login → VM views)
+// One ProxmoxClient per logged-in host — several standalone Proxmox hosts can
+// share the same root@pam credentials without being a real PVE cluster, so we
+// log into every host the user entered and merge their VM lists.
+let clients = [];
 
 // ---------- Window management ----------
 
@@ -120,34 +123,83 @@ ipcMain.handle('credentials:clear', () => {
 // ---------- IPC: Proxmox ----------
 
 ipcMain.handle('proxmox:login', async (_e, { host, username, password }) => {
-  try {
-    client = new ProxmoxClient(host);
-    await client.login(username, password);
-    createWindow('vms.html', 680, 520, true);
-    return { success: true };
-  } catch (err) {
-    return { success: false, error: err.message };
+  const hosts = String(host || '')
+    .split(',')
+    .map((h) => h.trim())
+    .filter(Boolean);
+
+  if (hosts.length === 0) {
+    return { success: false, error: 'Bitte mindestens einen Host angeben.' };
   }
+
+  const attempts = await Promise.all(
+    hosts.map(async (h) => {
+      const c = new ProxmoxClient(h);
+      try {
+        await c.login(username, password);
+        return { host: h, client: c, success: true };
+      } catch (err) {
+        return { host: h, success: false, error: err.message };
+      }
+    })
+  );
+
+  const succeeded = attempts.filter((a) => a.success);
+  const failed = attempts.filter((a) => !a.success);
+
+  if (succeeded.length === 0) {
+    // Single host → show the real error. Multiple hosts, all failing → the
+    // per-host errors are usually identical (wrong creds), so the first is enough.
+    return { success: false, error: attempts[0].error };
+  }
+
+  clients = succeeded;
+  createWindow('vms.html', 680, 520, true);
+
+  if (failed.length > 0) {
+    setImmediate(() => {
+      dialog.showMessageBox(mainWindow, {
+        type: 'warning',
+        title: 'Nicht alle Hosts erreichbar',
+        message: `${failed.length} von ${hosts.length} Host(s) konnten nicht angemeldet werden.`,
+        detail: failed.map((f) => `${f.host}: ${f.error}`).join('\n'),
+        buttons: ['OK'],
+      });
+    });
+  }
+
+  return { success: true };
 });
 
 ipcMain.handle('proxmox:getVMs', async () => {
   try {
-    const vms = await client.getSpiceVMs();
-    return { success: true, vms };
+    const perHost = await Promise.all(
+      clients.map(async ({ host, client }) => {
+        try {
+          const vms = await client.getSpiceVMs();
+          return vms.map((vm) => ({ ...vm, host }));
+        } catch {
+          return [];
+        }
+      })
+    );
+    return { success: true, vms: perHost.flat() };
   } catch (err) {
     return { success: false, error: err.message };
   }
 });
 
 ipcMain.handle('proxmox:logout', () => {
-  client = null;
+  clients = [];
   createWindow('login.html', 460, 500, false);
 });
 
-ipcMain.handle('proxmox:connect', async (_e, { node, vmid }) => {
+ipcMain.handle('proxmox:connect', async (_e, { host, node, vmid }) => {
   try {
-    const params = await client.getSpiceTicket(node, vmid);
-    const vvPath = buildVVFile(params, vmid);
+    const entry = clients.find((c) => c.host === host) || clients[0];
+    if (!entry) throw new Error('Nicht angemeldet.');
+    const params = await entry.client.getSpiceTicket(node, vmid);
+    const vvPath = buildVVFile(params, vmid, entry.client);
     launchRemoteViewer(vvPath);
     return { success: true };
   } catch (err) {
@@ -179,7 +231,7 @@ ipcMain.handle('settings:browseViewerPath', async () => {
 
 // ---------- SPICE helpers ----------
 
-function buildVVFile(params, vmid) {
+function buildVVFile(params, vmid, client) {
   const lines = ['[virt-viewer]', `type=${params.type || 'spice'}`];
 
   const host = params.proxy || params.host || client.host.split(':')[0];