feat(app-expo): env variants, local iOS prebuild, and About diagnostics

Align staging/production builds with APP_VARIANT bundle IDs, allow staging HTTP on iOS, add ios-prebuild scripts for TestFlight, and show connected API URL on About for non-production builds.

Co-authored-by: Cursor <cursoragent@cursor.com>

app-expo/src/core/config.ts

@@ -2,6 +2,26 @@ function trimTrailingSlashes(value: string): string {
   return value.replace(/\/+$/, '');
 }
 
+export type AppVariant = 'development' | 'staging' | 'production';
+
+function resolveAppVariant(): AppVariant {
+  const raw = process.env.EXPO_PUBLIC_APP_VARIANT;
+  if (raw === 'development' || raw === 'staging' || raw === 'production') {
+    return raw;
+  }
+  if (__DEV__) {
+    return 'development';
+  }
+  return 'production';
+}
+
+/** Shown on About screen for dev/staging builds only. */
+export function shouldShowAboutBackendUrl(variant: AppVariant = appVariant): boolean {
+  return variant === 'development' || variant === 'staging';
+}
+
+export const appVariant = resolveAppVariant();
+
 export const config = {
   apiBaseUrl: trimTrailingSlashes(
     process.env.EXPO_PUBLIC_API_URL ?? 'http://192.168.10.151:8000',
@@ -10,6 +30,8 @@ export const config = {
     process.env.EXPO_PUBLIC_WS_URL ?? 'ws://192.168.10.151:8000',
   ),
   isDebugMode: __DEV__,
+  appVariant,
+  showAboutBackendUrl: shouldShowAboutBackendUrl(),
 
   api: {
     timeoutMs: 30_000,