Revert "DROP VssHeaderProvier"

This reverts commit 651c95a.

Author: tnull

bindings/ldk_node.udl

@@ -138,6 +138,8 @@ interface Builder {
 	Node build_with_vss_store(NodeEntropy node_entropy, string vss_url, string store_id, string lnurl_auth_server_url, record<string, string> fixed_headers);
 	[Throws=BuildError]
 	Node build_with_vss_store_and_fixed_headers(NodeEntropy node_entropy, string vss_url, string store_id, record<string, string> fixed_headers);
+	[Throws=BuildError]
+	Node build_with_vss_store_and_header_provider(NodeEntropy node_entropy, string vss_url, string store_id, VssHeaderProvider header_provider);
 };
 
 interface Node {
@@ -398,6 +400,20 @@ enum BuildError {
 	"AsyncPaymentsConfigMismatch",
 };
 
+[Remote, Trait]
+interface VssHeaderProvider {
+	[Async, Throws=VssHeaderProviderError]
+	record<string, string> get_headers([ByRef]sequence<u8> request);
+};
+
+[Remote, Error]
+enum VssHeaderProviderError {
+	"InvalidData",
+	"RequestError",
+	"AuthorizationError",
+	"InternalError",
+};
+
 [Remote]
 enum PaymentFailureReason {
 	"RecipientRejected",

src/builder.rs

@@ -990,6 +990,33 @@ impl ArcedNodeBuilder {
 			.map(Arc::new)
 	}
 
+	/// Builds a [`Node`] instance with a [VSS] backend and according to the options
+	/// previously configured.
+	///
+	/// Given `header_provider` is used to attach headers to every request made
+	/// to VSS.
+	///
+	/// **Caution**: VSS support is in **alpha** and is considered experimental.
+	/// Using VSS (or any remote persistence) may cause LDK to panic if persistence failures are
+	/// unrecoverable, i.e., if they remain unresolved after internal retries are exhausted.
+	///
+	/// [VSS]: https://github.com/lightningdevkit/vss-server/blob/main/README.md
+	pub fn build_with_vss_store_and_header_provider(
+		&self, node_entropy: Arc<NodeEntropy>, vss_url: String, store_id: String,
+		header_provider: Arc<dyn VssHeaderProvider>,
+	) -> Result<Arc<Node>, BuildError> {
+		self.inner
+			.read()
+			.unwrap()
+			.build_with_vss_store_and_header_provider(
+				*node_entropy,
+				vss_url,
+				store_id,
+				header_provider,
+			)
+			.map(Arc::new)
+	}
+
 	/// Builds a [`Node`] instance according to the options previously configured.
 	// Note that the generics here don't actually work for Uniffi, but we don't currently expose
 	// this so its not needed.

src/ffi/types.rs

@@ -41,6 +41,7 @@ pub use lightning_liquidity::lsps1::msgs::{
 };
 pub use lightning_types::payment::{PaymentHash, PaymentPreimage, PaymentSecret};
 pub use lightning_types::string::UntrustedString;
+pub use vss_client::headers::{VssHeaderProvider, VssHeaderProviderError};
 
 use crate::builder::sanitize_alias;
 pub use crate::config::{