Every document-scoped key now goes through docKey(), which hangs it off the
tab's document id; the first document keeps the empty id, so existing browser
copies read back unchanged. A fresh tab takes up the most recently used
document no live tab holds, else starts a new one — one signed timestamp per
document (edentext-live@id) says which, written only by the tab holding it.
Snapshots and embedded fonts get a database per document. The picture store
stays shared and content-addressed, so its sweep now drops only keys no stored
document names any more, instead of the open document's own.
A handful of photos is the whole ~5 MB quota, and past it the document
stopped saving. The autosaved JSON now keeps an `idb:<key>` per picture
and the bytes live in their own store; the key is a sampled content
hash, so a picture used twice is stored once and each save sweeps what
the document no longer names.
loadDocument is async as a result and Editor.svelte awaits it. Where
IndexedDB is unavailable the data-URIs stay inline exactly as before.
Steffen Becker