# Change: Improve File Display in Chat and Fix Timezone Issues

## Why
Currently, uploaded files and images only appear in the "file drawer" sidebar, making it difficult to understand the context of when and why a file was uploaded. This also impacts AI report generation, as the AI cannot associate files with the conversation context. Additionally, some parts of the application still display times in GMT+0 instead of GMT+8.

## What Changes
- **BREAKING**: Message creation when uploading files - files now generate a linked message in chat
- Display uploaded files and images inline in the chat conversation
- Add image preview functionality with lightbox
- Show image thumbnails in chat messages (expandable to full size)
- Non-image files display with file type icons
- Update upload interface to show preview before sending
- Update AI report data collection to include file context (associated messages)
- Fix remaining GMT+0 timestamp displays to use GMT+8

## Impact
- Affected specs: file-storage, realtime-messaging, ai-report-generation
- Affected code:
  - Backend: `app/modules/file_storage/router.py`, `app/modules/realtime/` (message creation on upload)
  - Backend: `app/modules/report_generation/services/report_data_service.py`
  - Frontend: `frontend/src/pages/RoomDetail.tsx`
  - Frontend: New components `FileMessage.tsx`, `ImagePreview.tsx`
  - Database: May need migration to add `message_id` FK to `tr_room_files`