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/podcast/models.py

@@ -101,6 +101,8 @@ class PodcastSceneLine(BaseModel):
     speaker: str
     text: str
     emphasis: Optional[bool] = False
+    id: Optional[str] = None  # Optional line ID for frontend tracking
+    usedFactIds: Optional[List[str]] = None  # Facts referenced in this line
 
 
 class PodcastScene(BaseModel):
@@ -111,6 +113,8 @@ class PodcastScene(BaseModel):
     approved: bool = False
     emotion: Optional[str] = None
     imageUrl: Optional[str] = None  # Generated image URL for video generation
+    audioUrl: Optional[str] = None  # Generated audio URL for this scene
+    imagePrompt: Optional[str] = None  # Original image generation prompt for video context
 
 
 class PodcastExaConfig(BaseModel):