Disable dangerous motor reset command after causing telescope reboot

The motor reset command (cmd 14003, inferred from a gap in the WsCmd enum)
caused the telescope to immediately reboot during live testing. The Android
app never uses ReqMotorReset — it only uses joystick (14006-14009), run
(14000) and stop (14002). Motor homing is handled internally by the firmware
during astro calibration or panorama operations.

Changes:
- MotorReset() now returns an error instead of sending the command
- CLI "motor reset" shows the disabled message
- Documented the incident and lessons in TEST_RESULTS.md
- Confirmed motor position query (cmd 14001) works but returns NEED_RESET
- Confirmed slew movements (all directions/speeds) work safely after reboot

💘 Generated with Crush

Assisted-by: Crush:glm-5.2

dwarfctl/cmd/dwarfctl/main.go

@@ -265,7 +265,7 @@ func cmdMotor() *cobra.Command {
 		},
 		&cobra.Command{
 			Use:   "reset <motor-id> [direction]",
-			Short: "Reset motor to home (0=back, 1=forward)",
+			Short: "Reset motor to home (DISABLED — causes reboot)",
 			Args:  cobra.RangeArgs(1, 2),
 			Run: func(_ *cobra.Command, args []string) {
 				id := parseInt32(args[0])
@@ -276,7 +276,6 @@ func cmdMotor() *cobra.Command {
 				scope, cleanup := dial()
 				defer cleanup()
 				must(scope.MotorReset(id, dir))
-				fmt.Printf("motor %d reset (dir=%v)\n", id, dir)
 			},
 		},
 		&cobra.Command{