Major changes:
- Built C# bindings for Breez Spark SDK from source using UniFFI
- Created local NuGet package infrastructure (Breez.Sdk.Spark v0.0.1)
- Replaced Breez.Sdk package reference with Breez.Sdk.Spark
- Updated BreezLightningClient to use async Spark SDK API
- Removed Greenlight-specific code (credentials, invite codes)
- Simplified BreezSettings (no more Greenlight fields)
- Updated BreezService for async client initialization
- Cleaned up BreezController (removed certificate upload logic)
Key differences in Spark SDK:
- Nodeless architecture (no Greenlight hosting required)
- Simplified configuration (only mnemonic + API key)
- All async methods (no BlockingBreezServices)
- Different payment flow (PrepareSendPayment + SendPayment)
The plugin now works with Breez's Spark protocol which provides
a self-custodial Lightning experience without infrastructure hosting.
Note: NuGet package must be built from spark-sdk source before use.
