walletSyncService and storageSyncService were near-identical copies (the "two
sync systems"). Extract the shared machinery into createEncryptedSyncItem() —
per-pubkey enable flags, conflict-checked push, cheap remote-exists check,
enable/disable/pull — so each service is now a thin config differing only in
d-tag, kind, availability, and buildPayload/applyPayload. Public surface
(isAvailable/isEnabled/hasRemote/push/pull/enable/disable + the *_DTAG export)
preserved; both dedicated suites pass (8).
Next (step 2): shared confirm dialog + consistent notifications + seamless
auto-sync in the two profile controllers (the user-facing UX unification).
Co-Authored-By: Claude Opus 4.8 <[email protected]>
