Features phase 2b: silent payments + nostr sync leave the core wallet

wallet.js drops from 2,374 to ~1,970 lines, holding only BIP84 on-chain
logic plus generic feature seams. New seams added this pass:
  registerBalanceExtra   extra confirmed/pending buckets
  registerInputProvider  extra spendable inputs for buildTx
  registerSendPreparer   destinations needing post-selection derivation
  registerInputSigner    non-BIP84 input signing
  registerHistoryProvider / registerScanHook / registerRealtimeHook /
  registerLoadHook / registerCacheExtension / registerCacheSavedHook

src/features/sp-wallet.js: the whole BIP-352 engine — key derivation,
worker-accelerated indexer scanning, the live indexer WebSocket, SP
outputs as spendable inputs, sp1 send preparation, and per-output-key
signing — installs via those seams (installSpWallet).

src/features/sync.js: nostr identity + encrypted cross-device state sync
plus its Settings card, installed via load/cache-saved/realtime hooks.
profileChip/nostrProfile move here-adjacent (into gifts, the only other
nostr consumer), so core app.js no longer imports nostr at all.

buildTx/sign are now feature-agnostic (input providers + preparers +
signers); _recomputeBalance* use the balance-extra registry, so a core
build with no SP no longer calls a missing spBalance() (that regression
dropped the minimal build into offline mode — caught by the smoke test).

New coverage: tools/sp-test.js drives two browser "devices" through an
SP send, indexer discovery, and an SP-input spend on the ark regtest
chain (needs tools/sp-indexer.js pointed at bitcoind:18543). Minimal
smoke now also asserts no SP/nostr code ships.

Minimal profile: 314KB, down from 412KB (full: 580KB). All suites green:
minimal smoke, sp-test, ark UI, gift lifecycle.

Co-Authored-By: Claude Fable 5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01QFAcD4V284DvYZZHP7Rxxy

1 files changed, 2 insertions, 1 deletions

diff --git a/src/features/index.js b/src/features/index.js
index 590020a..e63e816 100644
--- a/src/features/index.js
+++ b/src/features/index.js
@@ -8,9 +8,10 @@ import { giftsFeature } from './gifts.js';
 import { swapsFeature } from './swaps.js';
 import { arkFeature } from './ark.js';
 import { spFeature } from './sp.js';
+import { syncFeature } from './sync.js';
 
 // NB order is meaningful where hooks stack: gifts' receive takeover and
 // balance line come before ark's, matching the pre-plugin layout.
 export function buildFeatures(ctx) {
-  return [giftsFeature(ctx), swapsFeature(ctx), arkFeature(ctx), spFeature(ctx)];
+  return [giftsFeature(ctx), swapsFeature(ctx), arkFeature(ctx), spFeature(ctx), syncFeature(ctx)];
 }