Drop Deref indirection for SignerProvider

Reduces generics and verbosity across the codebase, should provide equivalent
behavior.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: valentinewallace

lightning/src/chain/chainmonitor.rs

@@ -260,12 +260,11 @@ pub struct AsyncPersister<
 	S: FutureSpawner,
 	L: Logger + MaybeSend + MaybeSync + 'static,
 	ES: EntropySource + MaybeSend + MaybeSync + 'static,
-	SP: Deref + MaybeSend + MaybeSync + 'static,
+	SP: SignerProvider + MaybeSend + MaybeSync + 'static,
 	BI: BroadcasterInterface + MaybeSend + MaybeSync + 'static,
 	FE: FeeEstimator + MaybeSend + MaybeSync + 'static,
 > where
 	K::Target: KVStore + MaybeSync,
-	SP::Target: SignerProvider + Sized,
 {
 	persister: MonitorUpdatingPersisterAsync<K, S, L, ES, SP, BI, FE>,
 	event_notifier: Arc<Notifier>,
@@ -276,13 +275,12 @@ impl<
 		S: FutureSpawner,
 		L: Logger + MaybeSend + MaybeSync + 'static,
 		ES: EntropySource + MaybeSend + MaybeSync + 'static,
-		SP: Deref + MaybeSend + MaybeSync + 'static,
+		SP: SignerProvider + MaybeSend + MaybeSync + 'static,
 		BI: BroadcasterInterface + MaybeSend + MaybeSync + 'static,
 		FE: FeeEstimator + MaybeSend + MaybeSync + 'static,
 	> Deref for AsyncPersister<K, S, L, ES, SP, BI, FE>
 where
 	K::Target: KVStore + MaybeSync,
-	SP::Target: SignerProvider + Sized,
 {
 	type Target = Self;
 	fn deref(&self) -> &Self {
@@ -295,18 +293,17 @@ impl<
 		S: FutureSpawner,
 		L: Logger + MaybeSend + MaybeSync + 'static,
 		ES: EntropySource + MaybeSend + MaybeSync + 'static,
-		SP: Deref + MaybeSend + MaybeSync + 'static,
+		SP: SignerProvider + MaybeSend + MaybeSync + 'static,
 		BI: BroadcasterInterface + MaybeSend + MaybeSync + 'static,
 		FE: FeeEstimator + MaybeSend + MaybeSync + 'static,
-	> Persist<<SP::Target as SignerProvider>::EcdsaSigner> for AsyncPersister<K, S, L, ES, SP, BI, FE>
+	> Persist<<SP as SignerProvider>::EcdsaSigner> for AsyncPersister<K, S, L, ES, SP, BI, FE>
 where
 	K::Target: KVStore + MaybeSync,
-	SP::Target: SignerProvider + Sized,
-	<SP::Target as SignerProvider>::EcdsaSigner: MaybeSend + 'static,
+	<SP as SignerProvider>::EcdsaSigner: MaybeSend + 'static,
 {
 	fn persist_new_channel(
 		&self, monitor_name: MonitorName,
-		monitor: &ChannelMonitor<<SP::Target as SignerProvider>::EcdsaSigner>,
+		monitor: &ChannelMonitor<<SP as SignerProvider>::EcdsaSigner>,
 	) -> ChannelMonitorUpdateStatus {
 		let notifier = Arc::clone(&self.event_notifier);
 		self.persister.spawn_async_persist_new_channel(monitor_name, monitor, notifier);
@@ -315,7 +312,7 @@ where
 
 	fn update_persisted_channel(
 		&self, monitor_name: MonitorName, monitor_update: Option<&ChannelMonitorUpdate>,
-		monitor: &ChannelMonitor<<SP::Target as SignerProvider>::EcdsaSigner>,
+		monitor: &ChannelMonitor<<SP as SignerProvider>::EcdsaSigner>,
 	) -> ChannelMonitorUpdateStatus {
 		let notifier = Arc::clone(&self.event_notifier);
 		self.persister.spawn_async_update_channel(monitor_name, monitor_update, monitor, notifier);
@@ -386,15 +383,15 @@ pub struct ChainMonitor<
 impl<
 		K: Deref + MaybeSend + MaybeSync + 'static,
 		S: FutureSpawner,
-		SP: Deref + MaybeSend + MaybeSync + 'static,
+		SP: SignerProvider + MaybeSend + MaybeSync + 'static,
 		C: Deref,
 		T: BroadcasterInterface + MaybeSend + MaybeSync + 'static,
 		F: FeeEstimator + MaybeSend + MaybeSync + 'static,
 		L: Logger + MaybeSend + MaybeSync + 'static,
 		ES: EntropySource + MaybeSend + MaybeSync + 'static,
 	>
 	ChainMonitor<
-		<SP::Target as SignerProvider>::EcdsaSigner,
+		<SP as SignerProvider>::EcdsaSigner,
 		C,
 		T,
 		F,
@@ -403,9 +400,8 @@ impl<
 		ES,
 	> where
 	K::Target: KVStore + MaybeSync,
-	SP::Target: SignerProvider + Sized,
 	C::Target: chain::Filter,
-	<SP::Target as SignerProvider>::EcdsaSigner: MaybeSend + 'static,
+	<SP as SignerProvider>::EcdsaSigner: MaybeSend + 'static,
 {
 	/// Creates a new `ChainMonitor` used to watch on-chain activity pertaining to channels.
 	///

lightning/src/events/bump_transaction/mod.rs

@@ -691,10 +691,13 @@ where
 ///
 /// [`Event::BumpTransaction`]: crate::events::Event::BumpTransaction
 // Note that updates to documentation on this struct should be copied to the synchronous version.
-pub struct BumpTransactionEventHandler<B: BroadcasterInterface, C: Deref, SP: Deref, L: Logger>
-where
+pub struct BumpTransactionEventHandler<
+	B: BroadcasterInterface,
+	C: Deref,
+	SP: SignerProvider,
+	L: Logger,
+> where
 	C::Target: CoinSelectionSource,
-	SP::Target: SignerProvider,
 {
 	broadcaster: B,
 	utxo_source: C,
@@ -703,11 +706,10 @@ where
 	secp: Secp256k1<secp256k1::All>,
 }
 
-impl<B: BroadcasterInterface, C: Deref, SP: Deref, L: Logger>
+impl<B: BroadcasterInterface, C: Deref, SP: SignerProvider, L: Logger>
 	BumpTransactionEventHandler<B, C, SP, L>
 where
 	C::Target: CoinSelectionSource,
-	SP::Target: SignerProvider,
 {
 	/// Returns a new instance capable of handling [`Event::BumpTransaction`] events.
 	///

lightning/src/events/bump_transaction/sync.rs

@@ -264,20 +264,22 @@ where
 ///
 /// [`Event::BumpTransaction`]: crate::events::Event::BumpTransaction
 // Note that updates to documentation on this struct should be copied to the synchronous version.
-pub struct BumpTransactionEventHandlerSync<B: BroadcasterInterface, C: Deref, SP: Deref, L: Logger>
-where
+pub struct BumpTransactionEventHandlerSync<
+	B: BroadcasterInterface,
+	C: Deref,
+	SP: SignerProvider,
+	L: Logger,
+> where
 	C::Target: CoinSelectionSourceSync,
-	SP::Target: SignerProvider,
 {
 	bump_transaction_event_handler:
 		BumpTransactionEventHandler<B, CoinSelectionSourceSyncWrapper<C>, SP, L>,
 }
 
-impl<B: BroadcasterInterface, C: Deref, SP: Deref, L: Logger>
+impl<B: BroadcasterInterface, C: Deref, SP: SignerProvider, L: Logger>
 	BumpTransactionEventHandlerSync<B, C, SP, L>
 where
 	C::Target: CoinSelectionSourceSync,
-	SP::Target: SignerProvider,
 {
 	/// Constructs a new instance of [`BumpTransactionEventHandlerSync`].
 	pub fn new(broadcaster: B, utxo_source: C, signer_provider: SP, logger: L) -> Self {