Avoid locking on clientRunning bool when the connection is aborted for whatever reason

We want to just signal this through the giveUpChan, we will manage the signal from
the waiter side and in case set it to false there. THis way we avoid locking,
which should allow the MDM down+wait_for_term_chan_signal_+up procedure

clientRunning is used to signal two different conditions here:

1. the initialization procedure is over (we have an engine)
2. the connection being up (or being attempted)

Probably these two functionalities should not alias, and the failure of the second condition
(because of any error) should just drive a reconnection (currently it's not happening,
and we silently go idle).
OR, mor probably, the two things are the SAME and there should not exist a case where
we did the "Up" initialization and connection attempt but we are not still attempting it.

client/server/server_connect_test.go

@@ -101,6 +101,7 @@ func TestCleanupConnection_ClearsConnectClient(t *testing.T) {
 	require.NoError(t, err)
 
 	assert.Nil(t, s.connectClient, "connectClient should be nil after cleanup")
+	assert.False(t, s.clientRunning, "clientRunning should be cleared after cleanup (intent = down)")
 }
 
 // TestCleanState_NilConnectClient validates that CleanState doesn't panic
@@ -144,17 +145,20 @@ func TestDownThenUp_StaleRunningChan(t *testing.T) {
 	_, cancel := context.WithCancel(context.Background())
 	s.actCancel = cancel
 
-	// Simulate Down(): cleanupConnection sets connectClient = nil
+	// Simulate Down(): cleanupConnection sets connectClient = nil and
+	// flips clientRunning to false (intent = down). The connectionGoroutineRunning state
+	// remains independent of intent — derived from clientGiveUpChan.
 	s.mutex.Lock()
 	err := s.cleanupConnection()
 	s.mutex.Unlock()
 	require.NoError(t, err)
 
-	// After cleanup: connectClient is nil, clientRunning still true
-	// (goroutine hasn't exited yet)
+	// After cleanup: connectClient is nil, clientRunning is false (intent
+	// cleared by cleanupConnection), connectionGoroutineRunning may still be true
+	// (goroutine teardown is independent of the intent flag).
 	s.mutex.Lock()
 	assert.Nil(t, s.connectClient, "connectClient should be nil after cleanup")
-	assert.True(t, s.clientRunning, "clientRunning still true until goroutine exits")
+	assert.False(t, s.clientRunning, "clientRunning should be cleared by cleanupConnection (intent = down)")
 	s.mutex.Unlock()
 
 	// waitForUp() returns immediately due to stale closed clientRunningChan