Harden BLE host link and expose latency tools in the dashboard.

Add BLE RTT/stream tests and live tick median in the UI, fix concurrent WebSocket writes and late BATTERY replies, and skip 2M PHY updates that assert under ESP-NOW coexistence.

Co-authored-by: Cursor <cursoragent@cursor.com>

goTool/host_managed.go

@@ -33,6 +33,7 @@ type managedHost struct {
 	sp          *serialPort
 	ble         *bleLink
 	otaActive   bool
+	pausePoll   bool // true while BLE latency tests run (pollers yield)
 	uartPort    string // remembered UART port for reconnect
 }
 
@@ -291,10 +292,32 @@ func (m *managedHost) exchangePayloadPoll(payload []byte, cmdName string) ([]byt
 	return m.exchangePayloadMode(true, payload, cmdName, readTimeout)
 }
 
+func (m *managedHost) beginPausePoll() bool {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+	if m.otaActive || m.pausePoll {
+		return false
+	}
+	m.pausePoll = true
+	return true
+}
+
+func (m *managedHost) endPausePoll() {
+	m.mu.Lock()
+	m.pausePoll = false
+	m.mu.Unlock()
+}
+
+func (m *managedHost) PollPaused() bool {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+	return m.pausePoll || m.otaActive
+}
+
 func (m *managedHost) exchangePayloadMode(poll bool, payload []byte, cmdName string, timeout time.Duration) ([]byte, error) {
 	m.mu.Lock()
 	defer m.mu.Unlock()
-	if m.otaActive {
+	if m.otaActive || (poll && m.pausePoll) {
 		return nil, errHostBusy
 	}
 	switch m.transport {
@@ -302,7 +325,7 @@ func (m *managedHost) exchangePayloadMode(poll bool, payload []byte, cmdName str
 		if m.ble == nil {
 			return nil, fmt.Errorf("BLE not connected")
 		}
-		resp, err := m.ble.exchangePayload(payload, cmdName)
+		resp, err := m.ble.exchangePayloadTimeout(payload, cmdName, timeout)
 		if err != nil {
 			m.invalidateLocked(err)
 		}