fix(cbf): call best_block_updated per matched block instead of once at tip

Pairs each transactions_confirmed call with an immediate
best_block_updated for the same height so LDK processes per-block state
transitions (claimable balances, Filter script registrations) correctly.

Author: febyeji

src/chain/cbf.rs

@@ -867,6 +867,12 @@ impl CbfChainSource {
 		// The compact block filter already matched our scripts (covering both
 		// created outputs and spent inputs), so we confirm every transaction
 		// from matched blocks and let LDK determine relevance.
+		//
+		// Each block's `transactions_confirmed` is immediately followed by
+		// `best_block_updated` for the same height, so LDK processes
+		// per-block state transitions (claimable balances, Filter script
+		// registrations) correctly instead of collapsing them into a single
+		// update at the tip.
 		let per_request_timeout =
 			Duration::from_secs(self.sync_config.timeouts_config.per_request_timeout_secs.into());
 		for (height, block_hash) in &matched {
@@ -881,7 +887,9 @@ impl CbfChainSource {
 			.await?;
 		}
 
-		// Update the best block tip.
+		// Advance to the chain tip. For blocks between the last matched
+		// block and the tip this is the only `best_block_updated` call,
+		// which is sufficient since those blocks contain no relevant txs.
 		let tip = sync_update.tip();
 		if let Some(tip_header) = sync_update.recent_history().get(&tip.height) {
 			for confirmable in &confirmables {
@@ -1299,10 +1307,11 @@ async fn confirm_block_transactions(
 	let block = &indexed_block.block;
 	let header = &block.header;
 	let txdata: Vec<(usize, &Transaction)> = block.txdata.iter().enumerate().collect();
-	if !txdata.is_empty() {
-		for confirmable in confirmables {
+	for confirmable in confirmables {
+		if !txdata.is_empty() {
 			confirmable.transactions_confirmed(header, &txdata, height);
 		}
+		confirmable.best_block_updated(header, height);
 	}
 	Ok(())
 }