feat: Improve podcast maker UX and fix bugs

Frontend:
- Add progress modals with educational content for analysis and voice cloning
- Improve tab navigation in AnalysisPanel (combine Titles, Hook, CTA into one tab)
- Fix tab styling to make inactive tabs visible
- Fix avatar 'Make Presentable' not updating preview (blob URL handling)
- Improve mobile responsiveness for avatar tabs
- Clean up verbose console logging (AnalysisPanel, demoMode, RobustCamera)
- Add sequential progress messages instead of cycling

Backend:
- Fix 'Depends object has no attribute get' error in auth and image editing
- Use get_session_for_user instead of get_db outside FastAPI DI context
- Reduce WARNING logs to DEBUG in audio handler
- Add proper emphasis boolean handling in script generation
- Add missing fields to PodcastScene and PodcastSceneLine models
- Fix voice cloning cost estimate display issue

frontend/src/utils/demoMode.ts

@@ -8,36 +8,46 @@
 const PRIMARY_STORAGE_KEY = 'enabled_features';
 const PRIMARY_ENV_KEY = 'REACT_APP_ENABLED_FEATURES';
 
+// Cache for enabled features to avoid repeated logging
+let cachedFeatures: Set<string> | null = null;
+
 /**
  * Get enabled features from localStorage or environment.
  * Returns a Set of enabled feature names.
  */
 export function getEnabledFeatures(): Set<string> {
+  // Return cached value if available
+  if (cachedFeatures) {
+    return cachedFeatures;
+  }
+
   // Check localStorage first
   const storageValue = localStorage.getItem(PRIMARY_STORAGE_KEY);
   if (storageValue) {
-    console.log('demoMode: Found in localStorage:', storageValue);
     const features = storageValue.toLowerCase().split(',').map(f => f.trim());
     if (features.includes('all')) {
-      return new Set(['all']);
+      cachedFeatures = new Set(['all']);
+      return cachedFeatures;
     }
-    return new Set(features.filter(f => f));
+    cachedFeatures = new Set(features.filter(f => f));
+    return cachedFeatures;
   }
 
   // Check environment variable
   const envValue = process.env[PRIMARY_ENV_KEY];
-  console.log('demoMode: ENV value for', PRIMARY_ENV_KEY, ':', envValue);
   if (envValue) {
     const features = envValue.toLowerCase().split(',').map(f => f.trim());
     if (features.includes('all')) {
-      return new Set(['all']);
+      cachedFeatures = new Set(['all']);
+      return cachedFeatures;
     }
-    return new Set(features.filter(f => f));
+    cachedFeatures = new Set(features.filter(f => f));
+    return cachedFeatures;
   }
 
   // Default: all features enabled
-  console.log('demoMode: No env var, returning default "all"');
-  return new Set(['all']);
+  cachedFeatures = new Set(['all']);
+  return cachedFeatures;
 }
 
 /**