Fix restore bug: all proofs had same secret; convert to streaming API

[Copilot]

During wallet restoration, all proofs were assigned the same secret and blinding factor. The matching logic used keyset IDs to pair signatures with blinded messages, but all messages in a batch share the same keyset ID, causing firstWhere to always return the first item.

Changes

Fixed signature-to-message matching

• Parse both outputs and signatures from NUT-09 restore response (was only parsing signatures)
• Match by index: outputs[i] ↔ signatures[i], then lookup blinded message by B_ value
• Fallback to exhaustive matching if outputs not provided by mint

// Before: always matched the first item
final matchingItem = messageMap.values.firstWhere(
  (item) => item.blindedMessage.id == signature.id,  // All have same keyset ID!
);

// After: match by B_ value from response
final blindedItem = messageMap[output.blindedMessage];  // Unique B_ value

Converted to streaming API

• Cashu.restore() now returns Stream<CashuRestoreResult> instead of Future
• Yields progress after each keyset processed
• Saves proofs and updates balances incrementally

await for (final result in wallet.restore(mintUrl: url, unit: 'sat')) {
  print('${result.totalProofsRestored} proofs restored');
}

Updated test

• Verifies each restored proof has unique secret
• Consumes stream and validates progress updates

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• dev.mint.camelus.app
  • Triggering command: /tmp/dart-sdk/bin/dartvm /tmp/dart-sdk/bin/dartvm --resolved_executable_name=/tmp/dart-sdk/bin/dart --executable_name=/tmp/dart-sdk/bin/dart --mark_main_isolate_as_system_isolate .dart_tool/pub/bin/test/test.dart-3.10.9.snapshot test/cashu/cashu_restore_test.dart (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

---

✨ Let Copilot coding agent set things up for you — coding agent works faster and does higher quality work when set up for your repo.

[codecov]

Codecov Report

❌ Patch coverage is 72.78481% with 43 lines in your changes missing coverage. Please review.
✅ Project coverage is 72.31%. Comparing base (0b2f5a2) to head (66f2c09).
⚠️ Report is 1 commits behind head on cashu-wallet.

Files with missing lines	Patch %	Lines
...lib/domain_layer/usecases/cashu/cashu_restore.dart	66.35%	36 Missing ⚠️
...data_layer/repositories/cashu/cashu_repo_impl.dart	85.00%	3 Missing ⚠️
...ges/ndk/lib/domain_layer/usecases/cashu/cashu.dart	87.50%	3 Missing ⚠️
...in_layer/entities/cashu/cashu_blinded_message.dart	66.66%	1 Missing ⚠️

Additional details and impacted files

@@               Coverage Diff                @@
##           cashu-wallet     #413      +/-   ##
================================================
+ Coverage         72.25%   72.31%   +0.05%     
================================================
  Files               177      179       +2     
  Lines              7612     7769     +157     
================================================
+ Hits               5500     5618     +118     
- Misses             2112     2151      +39     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.