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

backend/api/story_writer/utils/auth.py

@@ -8,9 +8,14 @@ def require_authenticated_user(current_user: Dict[str, Any] | None) -> str:
     Validates the current user dictionary provided by Clerk middleware and
     returns the normalized user_id. Raises HTTP 401 if authentication fails.
     """
-    if not current_user or not isinstance(current_user, dict):
+    # Guard against dependency injection issues where Depends object might be passed
+    if current_user is None or not isinstance(current_user, dict):
         raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED, detail="Authentication required")
-
+    
+    # Additional check: ensure it's actually a dict and not a Depends object or other type
+    if not hasattr(current_user, 'get') or not callable(getattr(current_user, 'get')):
+        raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED, detail="Invalid authentication context")
+    
     user_id = str(current_user.get("id", "")).strip()
     if not user_id:
         raise HTTPException(