🐛 Fix Stage 3 feature analysis display issue

- Add proper handling for feature_descriptions field (which is a list)
- Add detailed logging to debug stage result content
- Now properly displays actual VLM feature analysis instead of generic 'Analysis completed'

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

app.py

@@ -292,11 +292,26 @@ if current_image is not None:
             elif status == "completed":
                 stage_statuses[stage_key].success(f"✅ {stage_name}: Completed")
                 
-                # Extract content from stage data
+                # Extract content from stage data  
                 if isinstance(data, dict):
-                    content = data.get('description', 
-                             data.get('segmentation_guidance', 
-                             data.get('population_summary', 'Analysis completed')))
+                    logger.info(f"Stage {stage_key} data keys: {list(data.keys())}")
+                    
+                    # Handle different stage result formats
+                    content = data.get('description')
+                    if not content:
+                        content = data.get('segmentation_guidance')
+                    if not content:
+                        content = data.get('population_summary')
+                    if not content:
+                        # Stage 3 feature_descriptions is a list
+                        feature_descs = data.get('feature_descriptions', [])
+                        logger.info(f"Stage 3 feature_descriptions: {feature_descs}")
+                        if feature_descs and isinstance(feature_descs, list):
+                            content = '\n'.join(str(desc) for desc in feature_descs)
+                        else:
+                            content = 'Analysis completed'
+                    
+                    logger.info(f"Stage {stage_key} final content: {content[:100]}...")
                     
                     if content and content.startswith('```'):
                         lines = content.split('\n')