Tracking: cross-platform sync of Interface / Wallet / Zap preferences via NIP-78

[dmnyc]

Deferred phase

This issue tracks the work originally scoped in #556 / #564 / #569 (and iOS counterpart barrydeen/wisp-ios#173) to sync user preferences across devices using NIP-78 (kind 30078 app-specific data with NIP-44 encryption).

The slim-PR series #570–#576 landed the client-side UI and per-account scoping pieces of that work, but deliberately deferred the actual cross-device sync infrastructure so each PR could ship and be reviewed in isolation.

In scope when this is picked up

• NIP-78 publisher / subscriber — kind 30078 events keyed by a stable d tag (e.g. wisp-app-settings:v1, wisp-zap-presets:v1, wisp-wallet-meta:v1)
• NIP-44 encryption of the JSON body (preferences contain account-level state that should not be public)
• Schema versioning — v1 baseline matching iOS; bump on breaking changes
• Conflict resolution — last-write-wins by created_at, with a manual "Restore from relays" affordance (the UI hook already exists from feat(settings): NIP-78 cross-device sync of Interface preferences #564's earlier iteration but is currently inert)
• Opt-in toggle — Settings → Interface should expose an explicit Sync toggle off by default
• Cross-platform schema parity — Android + iOS must read/write identical JSON; coordinate any schema change across both repos

Out of scope (already landed)

• Per-account scoping of preferences storage (fix(settings): isolate instant-zap defaults per account #576) — InterfacePreferences.activePubkey + reload(pubkey) + per-key namespacing already done
• Instant-zap settings UI (feat(zap-sheet): iOS-layout rewrite + instant-zap settings + post-card long-press + pin Send #574)
• One-tap zap composer + per-account presets (feat(zap): hero-input composer + Edit Presets sheet + per-account presets + long-press wiring #575)
• Wallet polish + bolt glow + NWC connection redesign (already on main)

Superseded PRs (closed when this issue was filed)

• feat(zap): port iOS one-tap-zap + NIP-78 parity + wallet polish #556 — feat/one-tap-zap monolith
• feat(settings): NIP-78 cross-device sync of Interface preferences #564 — feat/nip78-settings-sync (Android side of the deferred sync)
• fix(settings): isolate instant-zap defaults per account #569 — fix/zap-defaults-account-isolation (superseded by fix(settings): isolate instant-zap defaults per account #576)
• feat(settings): NIP-78 cross-device sync of Interface preferences wisp-ios#173 — iOS side of the deferred sync

Suggested future-phase plan

1. Schema definition PR (both repos in lockstep) — define the kind-30078 JSON envelope, d tag namespacing, version field, encryption envelope. No actual sync wiring yet, just types + serialization.
2. Android publisher PR — write on every relevant SharedPreferences change, debounced
3. iOS publisher PR — equivalent
4. Subscriber + Restore UX (both repos) — on launch, fetch latest 30078 events for the user's pubkey, decrypt, surface a confirmation before overwriting local state (avoid surprise loss of local edits)
5. Settings toggle + "Restore from relays" button wiring on both platforms

Related

• Android slim PRs that landed: feat(wallet-setup): primary Spark mode + More-options accordion #570, feat(wallet): dashboard polish — top-5 transactions + switch flow + NWC dashboard + settings cleanup #571, fix(wallet): drop per-relay backup status list from Spark settings #572, feat(bolt): white-core glow pulse for in-flight zap #573, feat(zap-sheet): iOS-layout rewrite + instant-zap settings + post-card long-press + pin Send #574, feat(zap): hero-input composer + Edit Presets sheet + per-account presets + long-press wiring #575, fix(settings): isolate instant-zap defaults per account #576
• iOS PRs that landed: fix(settings): isolate instant-zap defaults per account wisp-ios#195 (per-account scoping) and the rest of the wallet/zap series