- Open queues every linked file's lookup (stat, then hash) for the background
check instead of stating candidates on the UI thread.
- links.list, links.update and relinkFolder use the open's status only while
its check is still running; afterwards the file is looked at as it is now.
- Preflight tells Modified from size, time and the remembered hash checks
(the worker keeps them between passes) and the vector test from the mime
type; it never loads a linked original.
- A modification time of 0 never vouches for a file's bytes.
- Migration keeps an unsettled time as UNVERIFIED_MTIME; recovery snapshots
keep images not yet saved as links embedded.
- Links panel test fixture has real files, so its Embedded assertions hold.
aiongg