Store Cashu proofs in one blob

Persist the complete Cashu proof set with one versioned KV write so
VSS-backed wallets avoid a round trip per proof. This should make
startup much faster for VSS based cashu wallets.

Author: benthecarman

orange-sdk/Cargo.toml

@@ -16,7 +16,7 @@ name = "orange_sdk"
 default = ["spark"]
 uniffi = ["dep:uniffi", "spark", "cashu", "rand", "pin-project-lite"]
 spark = ["breez-sdk-spark", "uuid", "serde_json"]
-cashu = ["cdk", "cdk/npubcash", "serde_json"]
+cashu = ["cdk", "cdk/npubcash", "serde", "serde_json"]
 _test-utils = ["corepc-node", 'electrsd', "cashu", "uuid/v7", "rand"]
 _cashu-tests = ["_test-utils", "cdk-ldk-node", "cdk/mint", "cdk-sqlite", "cdk-axum", "axum"]
 
@@ -32,6 +32,7 @@ breez-sdk-spark = { git = "https://github.com/breez/spark-sdk.git", rev = "0d8db
 tokio = { version = "1.0", default-features = false, features = ["rt-multi-thread", "sync", "macros"] }
 uuid = { version = "1.0", default-features = false, optional = true }
 cdk = { version = "0.16.0", default-features = false, features = ["wallet"], optional = true }
+serde = { version = "1.0", features = ["derive"], optional = true }
 serde_json = { version = "1.0", optional = true }
 async-trait = "0.1"
 log = "0.4.28"

orange-sdk/src/ffi/orange/config.rs

@@ -125,6 +125,10 @@ impl From<OrangeVssAuth> for VssAuth {
 /// failures are unrecoverable, i.e., if they remain unresolved after internal
 /// retries are exhausted.
 ///
+/// A VSS store must only be used by one active wallet instance at a time. Cashu
+/// proof mutations are serialized within one process, but separate instances can
+/// overwrite each other's proof snapshots.
+///
 /// [Versioned Storage Service (VSS)]: https://github.com/lightningdevkit/vss-server/blob/main/README.md
 #[derive(Debug, Clone, uniffi::Object)]
 pub struct VssConfig {

orange-sdk/src/lib.rs

@@ -218,6 +218,10 @@ pub enum VssAuth {
 /// failures are unrecoverable, i.e., if they remain unresolved after internal
 /// retries are exhausted.
 ///
+/// A VSS store must only be used by one active wallet instance at a time. Cashu
+/// proof mutations are serialized within one process, but separate instances can
+/// overwrite each other's proof snapshots.
+///
 /// [Versioned Storage Service (VSS)]: https://github.com/lightningdevkit/vss-server/blob/main/README.md
 #[derive(Debug, Clone)]
 pub struct VssConfig {