Update PID examples to use ObservableAnalogInput for consistency

Author: rzeldent

examples/PIDMotorSpeedControl/PIDMotorSpeedControl.cpp

@@ -14,7 +14,7 @@ using namespace Reactive;
 // Hardware: Encoder on pins 2&3, motor driver on pin 9, potentiometer on A0
 
 auto encoder = ObservableRotaryEncoder<RotaryEncoderData>(2, 3);
-auto potentiometer = AnalogInput(A0, 100);  // Read setpoint every 100ms
+auto potentiometer = ObservableAnalogInput(A0, 100);  // Read setpoint every 100ms
 auto speedTimer = IntervalMillis(250);  // Calculate speed every 250ms
 
 auto pidController = FilterPID<float>(0, 1.5, 0.2, 0.1, -255, 255);

examples/PIDTemperatureControl/PIDTemperatureControl.cpp

@@ -13,7 +13,7 @@ using namespace Reactive;
 // PID Temperature Controller Example
 // Hardware: Temperature sensor on A0, heater control on pin 9
 
-auto tempSensor = AnalogInput(A0, 200);  // Read temperature every 200ms
+auto tempSensor = ObservableAnalogInput(A0, 200);  // Read temperature every 200ms
 auto pidController = FilterPID<float>(25.0, 2.0, 0.1, 0.5, 0, 255);  // Setpoint 25°C, Kp=2.0, Ki=0.1, Kd=0.5
 
 const int HEATER_PIN = 9;