fix: Skip onboarding calls in podcast-only demo mode

- Add demoMode utility for consistent demo mode detection
- Skip onboarding API calls in OnboardingContext when in demo mode
- Redirect to /podcast-maker instead of /onboarding in demo mode

frontend/src/utils/demoMode.ts

@@ -0,0 +1,47 @@
+/**
+ * Demo mode detection utilities for podcast-only demo mode.
+ */
+
+const DEMO_MODE_STORAGE_KEYS = [
+  'app_mode',
+  'demo_mode',
+  'podcast_only_demo_mode',
+];
+
+const DEMO_MODE_ENV_KEYS = [
+  'REACT_APP_APP_MODE',
+  'REACT_APP_DEMO_MODE',
+  'REACT_APP_PODCAST_ONLY_DEMO_MODE',
+];
+
+/**
+ * Check if podcast-only demo mode is enabled.
+ * Checks localStorage first, then environment variables.
+ */
+export function isPodcastOnlyDemoMode(): boolean {
+  // Check localStorage
+  for (const key of DEMO_MODE_STORAGE_KEYS) {
+    const value = (localStorage.getItem(key) || '').toLowerCase();
+    if (value === 'true' || value === 'podcast-only' || value === 'podcast_only') {
+      return true;
+    }
+  }
+
+  // Check environment variables
+  for (const key of DEMO_MODE_ENV_KEYS) {
+    const value = (process.env[key] || '').toLowerCase();
+    if (value === 'true' || value === 'podcast-only' || value === 'podcast_only') {
+      return true;
+    }
+  }
+
+  return false;
+}
+
+/**
+ * Check if the app should skip onboarding entirely.
+ * Returns true in podcast-only demo mode.
+ */
+export function shouldSkipOnboarding(): boolean {
+  return isPodcastOnlyDemoMode();
+}