A manual Save during Publish sent a second save with the same base_rev; the
loser 409'd against its own tab (and could abort the publish).
- useWhpApi: every save runs through one in-flight promise (SaveGuard
saveInFlight). A save requested while one is out waits, then sends only
if still dirty, with the rev the first returned; payload is read from the
editor at send time. Forced (empty/overwrite) saves always send.
- Save buttons are disabled while publishing.
- Pill: a conflict reads 'Unsaved changes' (modal open) from Save and from
Publish alike; a never-saved site (load rev null) reads 'Not saved yet'.
- Autosave interval reads runSave through a ref, so editing can't keep
restarting it and starve autosave.
- Fix stale 'Throws like exportBodyHtml' comment.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
shadowdaoandClaude Opus 5.5
97ccbee461