fix: Multiple images not saving in new post creation

Problem:
- Only cover image was being saved when creating posts
- Section images were shown in preview but not sent to backend
- File inputs were not preserved after section saving

Solution:
- Store section files in global JavaScript storage
- Send all section images in FormData during form submission
- Update backend to process section_image_* files
- Add is_cover flag distinction between cover and section images
- Preserve file references throughout the editing process

Features:
- Multiple images per post section now work correctly
- Cover image marked with is_cover=True
- Section images marked with is_cover=False
- Proper file cleanup when images are removed
- Enhanced logging for debugging image uploads

app/routes/community.py

@@ -273,8 +273,8 @@ def new_post():
                                 original_name=cover_file.filename,
                                 size=result['size'],
                                 mime_type=result['mime_type'],
-                                post_id=post.id
-                                # Note: is_cover column missing, will be added in future migration
+                                post_id=post.id,
+                                is_cover=True  # Mark as cover image
                             )
                             db.session.add(cover_image)
                             current_app.logger.info(f'Cover image saved: {result["filename"]}')
@@ -300,6 +300,32 @@ def new_post():
                     except Exception as e:
                         current_app.logger.warning(f'Error processing GPX file: {str(e)}')
             
+            # Handle section images (multiple images from content sections)
+            section_images_processed = 0
+            for key in request.files.keys():
+                if key.startswith('section_image_') and not key.endswith('_section'):
+                    try:
+                        image_file = request.files[key]
+                        if image_file and image_file.filename:
+                            current_app.logger.info(f'Processing section image: {image_file.filename}')
+                            result = save_image(image_file, post.id)
+                            if result['success']:
+                                section_image = PostImage(
+                                    filename=result['filename'],
+                                    original_name=image_file.filename,
+                                    size=result['size'],
+                                    mime_type=result['mime_type'],
+                                    post_id=post.id,
+                                    is_cover=False  # Section images are not cover images
+                                )
+                                db.session.add(section_image)
+                                section_images_processed += 1
+                                current_app.logger.info(f'Section image saved: {result["filename"]}')
+                    except Exception as e:
+                        current_app.logger.warning(f'Error processing section image {key}: {str(e)}')
+            
+            current_app.logger.info(f'Total section images processed: {section_images_processed}')
+
             db.session.commit()
             current_app.logger.info(f'Post {post.id} committed to database successfully')