refactor(peripheral-demo): widen sensor state setters to accept null

- Update setTemperature, setHumidity, setAirPressure to accept number | null
- Keeps state API consistent with the nullable AppState field types

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: nicomiguelino

edge-apps/peripheral-integration-demo/src/core/state.ts

@@ -49,17 +49,17 @@ export function setLocale(locale: string) {
   notify()
 }
 
-export function setTemperature(value: number) {
+export function setTemperature(value: number | null) {
   state.temperature = value
   notify()
 }
 
-export function setHumidity(value: number) {
+export function setHumidity(value: number | null) {
   state.humidity = value
   notify()
 }
 
-export function setAirPressure(value: number) {
+export function setAirPressure(value: number | null) {
   state.airPressure = value
   notify()
 }