Игорь Надеин
53ec1a7b87
feat: implement Telegram-style image dimension pre-loading to fix auto-scroll
- Backend: added width/height fields to MessageAttachment model with Pillow auto-extraction
- Migration: 0021_add_image_dimensions + populate_image_dimensions management command
- API: serialize width/height in messageAttachmentSerializer and consumers.py
- Frontend: switched from CSS aspect-ratio to explicit pixel calculation (Telegram approach)
* messageRendererV2.js: calculate exact dimensions (maxWidth=500px, proportional height)
* Fixes scroll jump issue: images now reserve exact space before loading
* Debug logging added to validate dimension rendering
- Testing: 18/18 images populated successfully with dimensions
This prevents scroll position shifts when images load after initial positioning,
implementing the same approach as Telegram Web.
Related: scroll positioning, image preloading, chat UX