Enable host OTA over BLE and harden ESP-NOW slave distribution.

Allow the same staged firmware upload path on BLE as UART, fix distribute stack/event-group crashes, and recover sticky slave OTA sessions instead of failing with err=4.

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

goTool/main.go

@@ -29,7 +29,7 @@ func usage() {
 	fmt.Fprintf(os.Stderr, "  ble-stream    enable stream + measure BleStreamTick window\n")
 	fmt.Fprintf(os.Stderr, "  test          run automated scenario (see testdata/)\n")
 	fmt.Fprintf(os.Stderr, "  serve         web dashboard (optional -port / -ble; connect from UI)\n")
-	fmt.Fprintf(os.Stderr, "  ota           UART OTA upload (A/B partitions; UART host only)\n")
+	fmt.Fprintf(os.Stderr, "  ota           host OTA upload (A/B partitions; UART or BLE)\n")
 	fmt.Fprintf(os.Stderr, "  ota-progress  query per-slave ESP-NOW OTA progress on master\n")
 	fmt.Fprintf(os.Stderr, "  led-ring      set LED ring progress bar (0–100%%, rgb, intensity)\n")
 	fmt.Fprintf(os.Stderr, "  find-me       blink LED ring red/green/blue (3× each, full brightness)\n")
@@ -83,13 +83,6 @@ func main() {
 			usage()
 			os.Exit(2)
 		}
-		if cmd == "ota" || cmd == "ota-progress" || cmd == "ota_progress" {
-			if *useBLE {
-				fmt.Fprintf(os.Stderr, "OTA requires UART host (DIP8=0, -port)\n")
-				os.Exit(2)
-			}
-		}
-
 		var h hostConn
 		if *useBLE {
 			bl, err := openBLE(*bleName, time.Duration(*bleSettle*float64(time.Second)))
@@ -187,11 +180,19 @@ func main() {
 			}
 			runErr = runLogLevel(sp, flag.Args()[1:])
 		case "ota":
-			sp := h.(*serialPort)
-			runErr = runOTA(sp, flag.Args()[1:])
+			t, ok := h.(otaTransport)
+			if !ok {
+				runErr = fmt.Errorf("ota: unsupported host transport")
+				break
+			}
+			runErr = runOTA(t, flag.Args()[1:])
 		case "ota-progress", "ota_progress":
-			sp := h.(*serialPort)
-			runErr = runOtaProgress(sp, flag.Args()[1:])
+			t, ok := h.(otaTransport)
+			if !ok {
+				runErr = fmt.Errorf("ota-progress: unsupported host transport")
+				break
+			}
+			runErr = runOtaProgress(t, flag.Args()[1:])
 		}
 	default:
 		fmt.Fprintf(os.Stderr, "unknown command %q\n\n", cmd)