fix(desktop): make the zsh probe test legs visible and run them on CI

The zsh login-shell legs in remote-lifecycle.test.ts and
ssh-connection.test.ts silently returned when zsh was missing, and the
js-tests runner image ships no zsh, so the #111949 coverage never ran on
CI and a wrapper regression stayed green.

- js-tests.yml: install zsh on the Linux runner before the checks.
- Both legs now report vitest skips ('zsh not installed') instead of
  passing; the ssh-connection leg is its own test so the skip is visible.
- Docs: note the zsh degraded mode (no process-group kill for a hung
  probe's grandchildren) in the SSH connection guide.

.github/workflows/js-tests.yml

@@ -23,6 +23,13 @@ jobs:
           node-version: 26
           cache: npm
 
+      # The desktop SSH watchdog tests run their probe through a real zsh
+      # login shell (#111949). The ubuntu image ships no zsh and the tests
+      # skip without it, so install it here or those legs never run on CI.
+      - name: Install zsh
+        if: runner.os == 'Linux'
+        run: sudo apt-get install -y zsh
+
       - name: grab npm 12
         run: |
           # No-op once the bundled npm is already 12.x — saves ~5-15s/job and

apps/desktop/electron/remote-lifecycle.test.ts

@@ -1813,17 +1813,17 @@ test('remote SSH ownership capability requires both secure bootstrap flags', asy
   assert.equal(await remoteSupportsSshOwnership(unsupported, '/x/hermes'), false)
 })
 
-test('capability probe survives a zsh login shell on the remote (#111949)', async () => {
-  if (process.platform === 'win32') {
-    return
-  }
-
+test.skipIf(process.platform === 'win32')('capability probe survives a zsh login shell on the remote (#111949)', async t => {
   // sshd runs the remote command under the account's LOGIN shell. A bare
   // `set -m` is fatal in a non-interactive zsh, so the watchdog-wrapped probe
   // used to return nothing and a current remote was reported as unsupported.
   const zsh = await exec('command -v zsh || true').then(r => r.stdout.trim())
 
+  // CI installs zsh (js-tests.yml); locally a missing zsh must show as a
+  // skip, not a pass, or a wrapper regression stays green unnoticed.
   if (!zsh) {
+    t.skip('zsh not installed')
+
     return
   }
 

apps/desktop/electron/ssh-connection.test.ts

@@ -1074,6 +1074,25 @@ test('stopTunnelChild waits for process exit', async () => {
   assert.equal(stopped, true)
 })
 
+test.skipIf(process.platform === 'win32')('withRemoteTimeout runs a healthy probe under a zsh login shell (#111949)', async t => {
+  // SSH runs the remote command through the account's login shell. In
+  // non-interactive zsh, a bare `set -m` is fatal, so the wrapper must still
+  // run a healthy probe rather than reporting the remote as unsupported.
+  const zsh = await execFileAsync('sh', ['-c', 'command -v zsh || true']).then(r => r.stdout.trim())
+
+  // CI installs zsh (js-tests.yml); locally a missing zsh must show as a
+  // skip, not a pass, or a wrapper regression stays green unnoticed.
+  if (!zsh) {
+    t.skip('zsh not installed')
+
+    return
+  }
+
+  const { stdout: zshStdout } = await execFileAsync(zsh, ['-fc', withRemoteTimeout('echo zsh-ok', 5)])
+
+  assert.equal(zshStdout, 'zsh-ok\n')
+})
+
 test('withRemoteTimeout kills a hung probe remotely instead of orphaning it (#110478)', async () => {
   if (process.platform === 'win32') {
     return
@@ -1092,17 +1111,6 @@ test('withRemoteTimeout kills a hung probe remotely instead of orphaning it (#11
   )
   assert.ok(REMOTE_PROBE_TIMEOUT_SECS * 1000 < 20_000, 'remote watchdog fires before the local exec timeout')
 
-  // SSH runs the remote command through the account's login shell. In
-  // non-interactive zsh, a bare `set -m` is fatal, so the wrapper must still
-  // run a healthy probe rather than reporting the remote as unsupported.
-  const zsh = await execFileAsync('sh', ['-c', 'command -v zsh || true']).then(r => r.stdout.trim())
-
-  if (zsh) {
-    const { stdout: zshStdout } = await execFileAsync(zsh, ['-fc', withRemoteTimeout('echo zsh-ok', 5)])
-
-    assert.equal(zshStdout, 'zsh-ok\n')
-  }
-
   // Behavior through a real POSIX shell: healthy output passes through …
   const healthyStart = Date.now()
   const { stdout } = await execFileAsync('sh', ['-c', withRemoteTimeout('echo hello', 5)])

website/docs/user-guide/multi-connection-desktop.md

@@ -130,7 +130,10 @@ authentication; manage sign-in from the registered connection controls.
    - *SSH only:*
      - **SSH host** — one composite field in `user@host:22` form (user and
        port optional). Your SSH key is used; the app adopts a dashboard
-       token over the tunnel.
+       token over the tunnel. Remote probes run under the account's login
+       shell; on a `zsh` login shell the probe watchdog cannot kill the whole
+       process group, so a hung probe's grandchildren may linger on the remote
+       (bash/sh remotes reap them).
 5. Click **Save connection** (or **Cancel**).
 6. Click **Test** on the new row and wait for *"Reachable"*.