Add TX device-verification region to debug config

Add a US-TX region to the debug config with verificationMethods
['device', 'kws'], plus a useRealDeviceSignalsAPI escape hatch (default
off) so the real native age API can be exercised in debug mode instead of
the faked deviceSignals.

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

src/ageAssurance/data.tsx

@@ -503,7 +503,8 @@ export function createDeviceSignalsQueryKey({did}: {did: string}) {
 export async function getDeviceSignals(): Promise<
   AgeRange.AgeRangeResponse | undefined
 > {
-  if (debug.enabled) return debug.resolve(debug.deviceSignals)
+  if (debug.enabled && !debug.useRealDeviceSignalsAPI)
+    return debug.resolve(debug.deviceSignals)
   if (!IS_NATIVE) return undefined
   try {
     return await AgeRange.requestAgeRangeAsync({