The fallback provider introduced in 5aeb2fd3 wrapped containerfs but did
not implement storage.ContainerFileOpener, causing IngestContainerFile to
fail with "provider does not support container file reading". This broke
outbound file attachments on all IM channels (Telegram, Discord, etc.)
because container paths like /data/xxx.xlsx were passed as-is to the
platform API instead of being ingested into the media store first.
- Add localfs storage provider as fallback when containerfs is unreachable
- Wrap media service with fallback provider in both entry points
- Fix gallery lightbox src matching by comparing pathnames only