Pull before push
Outline
Slovníček stores its vocabulary in IndexedDB and treats it as the source of truth, not as a cache. That one decision creates the hardest problem in the whole project: when the same row has been edited in two places, which edit wins?
The naive version, and why it loses data
Describe the first implementation: push local changes, then pull remote ones. Show the interleaving where a stale offline edit silently overwrites a newer server row.
Ordering is the fix, not conflict resolution
Explain why pulling first is what makes last-write-wins safe, rather than the comparison itself. The comparison was never the hard part.
Watermarks per table, not per database
Why a single global "last synced at" is not enough once tables sync at different rates, and what a per-table watermark buys.
What still goes wrong
Be honest here: clock skew between client and server, and what the design does about it.