test: a conversation stuck on an Agent must not stop another from using it

End-to-end version of the blocking fix, on the real LocalWorkspace: one direct
chat's turn never finishes, and a second direct chat with the same Agent has to
answer anyway while the first is still marked running. On the commit before the
fix this test times out, which is the symptom that was reported (the second
conversation sat on 'waiting for another Agent that is writing in the same
folder' until the first finished).

desktop/test/workspace/local-workspace-write-scheduling.test.cjs

@@ -186,6 +186,44 @@ test('the same Agent answers in two conversations at once', { timeout: 10000 },
   assert.equal(scheduler.snapshot().active.global, 0)
 })
 
+test('a conversation stuck on an Agent does not stop another conversation from using it', { timeout: 10000 }, async (t) => {
+  const { directory, options } = fixture()
+  const stuck = deferred()
+  t.after(() => {
+    stuck.resolve()
+    fs.rmSync(directory, { recursive: true, force: true })
+  })
+  options.runScheduler = new RunScheduler()
+  options.runAgent = async (agent, prompt) => {
+    // The first conversation's turn never finishes by itself.
+    if (prompt.includes('stay busy')) await stuck.promise
+    return { text: `${agent.kind} answered: ${prompt.includes('quick') ? 'quick' : 'other'}` }
+  }
+  const workspace = new LocalWorkspace(options)
+  await workspace.refreshAgents()
+  const [busy, free] = [1, 2].map(number => workspace.createGroup({
+    name: `Hermes chat ${number}`, agentKinds: ['hermes'], directAgentKind: 'hermes',
+    conversationType: 'direct', workdir: directory, allowWrite: true,
+  }))
+
+  const first = workspace.sendMessage({ groupId: busy.id, text: 'stay busy' })
+  await new Promise(resolve => setTimeout(resolve, 20))
+  assert.equal(workspace.snapshot().runningGroupIds.includes(busy.id), true)
+
+  // The second conversation answers while the first is still running.
+  await workspace.sendMessage({ groupId: free.id, text: 'a quick question' })
+  const answers = workspace.snapshot().messages.filter(message => (
+    message.groupId === free.id && message.role === 'agent'
+  ))
+  assert.equal(answers.length, 1)
+  assert.match(answers[0].content, /quick/)
+  assert.equal(workspace.snapshot().runningGroupIds.includes(busy.id), true, 'the first is still running')
+  assert.equal(workspace.snapshot().runningGroupIds.includes(free.id), false)
+
+  stuck.resolve()
+  await first
+})
+
 test('Manual V4 retains parallel readers alongside its single writer and stable message order', { timeout: 10000 }, async (t) => {
   const { directory, options } = fixture()
   const release = deferred()