The fallback download shows a one-time hint about the browser's
ask-where-to-save setting, keeps its anchor in the DOM and the blob
URL alive past the click (Gecko). Failed saves and exports now report
the underlying error, with a clear message when a script blocker
prevented a lazy chunk from loading. A full or blocked localStorage
no longer fails the save when recording the recent-files entry.
Ctrl+S always built .odt bytes and wrote them into whatever handle was
open — including a handle obtained by opening a .docx, silently
overwriting it with ODF content under its old name. Track the loaded
format and route Save through the matching exporter and handle; the
title's extension label now reflects it instead of a hardcoded .odt.
Save As stays .odt-only, so it switches the format back.
The manifest registers .odt/.ott/.docx/.dotx as file handlers and a
launchQueue consumer opens what the OS passes, keeping the handle so the
first Save writes that file. A .dotx now reads like an .ott: Word's
importer, but never bound as the file to save over.
A .ott/.dotx is the built document with one label changed — ODF's
package media type, Word's content type for the document part — so the
picker offers both and the chosen extension decides which exporter runs.
Opening or saving also records the file in a recent list. The name is in
localStorage so the menu draws at once; the handle that reopens it is in
IndexedDB beside it. A file that has moved, or whose permission the
browser drops on reload, is reported and dropped from the list.
Steffen Becker