Rename device-signals debug flag to useMockDeviceSignalsAPIResponse

Invert the flag's polarity and name so it reads like the other "enable"
booleans in the debug module: useMockDeviceSignalsAPIResponse defaults to
true (mock the native response), set false to hit the real API.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/ageAssurance/data.tsx

@@ -503,7 +503,7 @@ export function createDeviceSignalsQueryKey({did}: {did: string}) {
 export async function getDeviceSignals(): Promise<
   AgeRange.AgeRangeResponse | undefined
 > {
-  if (debug.enabled && !debug.useRealDeviceSignalsAPI)
+  if (debug.enabled && debug.useMockDeviceSignalsAPIResponse)
     return debug.resolve(debug.deviceSignals)
   if (!IS_NATIVE) return undefined
   try {

src/ageAssurance/debug.ts

@@ -28,11 +28,12 @@ export const geolocation: Geolocation | undefined = enabled
   : undefined
 
 /**
- * When debug is enabled we normally fake `deviceSignals` too. Flip this to hit
- * the real native age API (`expo-age-range`) so the OS age prompt actually
- * shows — useful for testing the device flow on a physical device.
+ * When debug is enabled we mock the `deviceSignals` response by default. Set
+ * this to `false` to hit the real native age API (`expo-age-range`) so the OS
+ * age prompt actually shows — useful for testing the device flow on a physical
+ * device.
  */
-export const useRealDeviceSignalsAPI = false
+export const useMockDeviceSignalsAPIResponse = true
 
 const deviceGeolocationEnabled = false || IS_E2E
 export const deviceGeolocation: Geolocation | undefined =