Saves push silently as before, but if the relay copy is NEWER than the one this
device last pushed (another device changed it), the user is now asked to confirm
before overwriting — preventing a silent multi-device clobber. No nag on normal
saves.
- js/services/settingsSyncFlags.js: track per-pubkey+kind last-pushed created_at
(getSyncPushedAt/setSyncPushedAt).
- js/services/syncConflict.js: pushWithConflictCheck — peek remote created_at
(list-only, no decrypt), compare to last push, call confirmOverwrite only on a
real conflict, then push strictly-newer than remote so the replace wins.
- storage/walletSyncService push()/enable() route through it and accept a
confirmOverwrite callback.
- ProfileStorage/WalletController supply confirmOverwrite (window.confirm) and
surface a "kept the newer copy" status when the user declines.
tests/sync-conflict.test.mjs: no-remote→silent, newer→prompt(+decline blocks
push), confirm→strictly-newer push, older→no prompt. Mutation-verified
(ignoring the decline fails). Service-test twins gained exists().
Co-Authored-By: Claude Opus 4.8 <[email protected]>
