fix(remote): disable the new-session button on remote project groups

public/sidebar.js

@@ -759,7 +759,12 @@ function renderProjects(projects, resort) {
     const newBtn = document.createElement('button');
     newBtn.className = 'project-new-btn';
     newBtn.innerHTML = '<svg width="12" height="12" viewBox="0 0 12 12" fill="none" stroke="currentColor" stroke-width="1.5"><line x1="6" y1="2" x2="6" y2="10"/><line x1="2" y1="6" x2="10" y2="6"/></svg>';
-    newBtn.title = 'New session';
+    if (project.remoteAlias) {
+      newBtn.disabled = true;
+      newBtn.title = 'Read-only mirror of ' + project.remoteAlias + ' — new sessions must be started on that host';
+    } else {
+      newBtn.title = 'New session';
+    }
     header.appendChild(newBtn);
 
     const sessionsList = buildSessionsList(fId, visible, older, subagentIndex, project.projectPath);
@@ -924,7 +929,11 @@ function rebindSidebarEvents(projects) {
     if (!header) continue;
     const newBtn = header.querySelector('.project-new-btn');
     if (newBtn) {
-      newBtn.onclick = (e) => { e.stopPropagation(); showNewSessionPopover(project, newBtn); };
+      if (project.remoteAlias) {
+        newBtn.onclick = (e) => e.stopPropagation();
+      } else {
+        newBtn.onclick = (e) => { e.stopPropagation(); showNewSessionPopover(project, newBtn); };
+      }
     }
     const scheduleBtn = header.querySelector('.project-schedule-btn');
     if (scheduleBtn) {

public/style.css

@@ -576,6 +576,20 @@ body { display: flex; flex-direction: column; }
   color: #5ec46a;
 }
 
+.project-new-btn:disabled {
+  cursor: default;
+  opacity: 0.4;
+}
+
+.project-new-btn:disabled:hover {
+  background: transparent;
+  color: #808098;
+}
+
+.project-header:hover .project-new-btn:disabled {
+  opacity: 0.4;
+}
+
 .project-archive-btn:hover {
   background: rgba(120,130,255,0.1);
   color: #8088ff;

test/dom-sidebar-remote-project-new-btn.test.js

@@ -0,0 +1,76 @@
+// Issue #214: a project group mirrored from an SSH host has no local
+// filesystem to spawn a PTY in. The "+" new-session button in its header
+// must not let a click reach launchNewSession/open-terminal with isNew and
+// the remote host's projectPath.
+
+const test = require('node:test');
+const assert = require('node:assert/strict');
+
+const { setupSidebarDom, makeSampleProject } = require('./dom-setup');
+
+function remoteProject() {
+  return makeSampleProject({
+    projectPath: '/srv/supervision',
+    folder: 'planificator::-srv-supervision',
+    remoteAlias: 'planificator',
+    sessions: [{
+      sessionId: 'remote-1',
+      summary: 'ripcord protocol',
+      modified: '2026-09-06T10:00:00.000Z',
+      starred: false,
+      archived: 0,
+      messageCount: 4,
+      projectPath: '/srv/supervision',
+      remoteAlias: 'planificator',
+    }],
+  });
+}
+
+test('the new-session button of a remote project group is disabled', () => {
+  const ctx = setupSidebarDom();
+  try {
+    ctx.sidebar.renderProjects([remoteProject()], true);
+    const fId = ctx.sidebar.folderId('/srv/supervision');
+    const header = ctx.document.getElementById('ph-' + fId);
+    const newBtn = header.querySelector('.project-new-btn');
+    assert.ok(newBtn, 'the button must still render');
+    assert.equal(newBtn.disabled, true);
+    assert.match(newBtn.title, /planificator/);
+  } finally { ctx.destroy(); }
+});
+
+test('clicking the new-session button of a remote project group opens nothing', () => {
+  const ctx = setupSidebarDom();
+  try {
+    ctx.sidebar.renderProjects([remoteProject()], true);
+    const fId = ctx.sidebar.folderId('/srv/supervision');
+    const header = ctx.document.getElementById('ph-' + fId);
+    const newBtn = header.querySelector('.project-new-btn');
+
+    const popovers = [];
+    ctx.window.showNewSessionPopover = (project, btn) => popovers.push(project.projectPath);
+
+    newBtn.onclick({ stopPropagation: () => {} });
+
+    assert.deepEqual(popovers, [], 'showNewSessionPopover must never be invoked for a remote project group');
+  } finally { ctx.destroy(); }
+});
+
+test('a local project group is unaffected: the new-session button stays enabled and wired', () => {
+  const ctx = setupSidebarDom();
+  try {
+    ctx.sidebar.renderProjects([makeSampleProject()], true);
+    const fId = ctx.sidebar.folderId('/home/dev/myproj');
+    const header = ctx.document.getElementById('ph-' + fId);
+    const newBtn = header.querySelector('.project-new-btn');
+    assert.equal(newBtn.disabled, false);
+    assert.equal(newBtn.title, 'New session');
+
+    const popovers = [];
+    ctx.window.showNewSessionPopover = (project, btn) => popovers.push(project.projectPath);
+
+    newBtn.onclick({ stopPropagation: () => {} });
+
+    assert.deepEqual(popovers, ['/home/dev/myproj']);
+  } finally { ctx.destroy(); }
+});