Images and videos sent from Chatwoot to LINE inboxes fail to display on
the LINE mobile app — users see expired markers, broken thumbnails, or
missing images. This happens because LINE mobile lazy-loads images
rather than downloading them immediately, and the ActiveStorage signed
URLs expire after 5 minutes.
Closes
https://linear.app/chatwoot/issue/CW-6696/line-messaging-with-image-or-video-may-not-show-when-client-inactive
## How to reproduce
1. Create a LINE inbox and start a chat from the LINE mobile app
2. Close the LINE mobile app
3. Send an image from Chatwoot to that chat
4. Wait 7-8 minutes (past the 5-minute URL expiration)
5. Open the LINE mobile app — the image is broken/expired
## What changed
- **`originalContentUrl`**: switched from `download_url` (signed, 5-min
expiry) to `file_url` (permanent redirect-based URL)
- **`previewImageUrl`**: switched to `thumb_url` (250px resized
thumbnail meeting LINE's 1MB/240x240 recommendation), with fallback to
`file_url` for non-image attachments like video
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Co-authored-by: Sojan Jose <sojan@pepalo.com>
4cce7f6ad8