Use inbound SCID alias for blinded path creation

lightning/src/ln/channel.rs

@@ -9403,6 +9403,12 @@ where
 		false
 	}
 
+	/// Gets the latest inbound SCID alias from our peer, or if none exists, the channel's real
+	/// SCID.
+	pub fn get_inbound_scid(&self) -> Option<u64> {
+		self.context.latest_inbound_scid_alias.or(self.funding.get_short_channel_id())
+	}
+
 	/// Returns true if our channel_ready has been sent
 	pub fn is_our_channel_ready(&self) -> bool {
 		matches!(self.context.channel_state, ChannelState::AwaitingChannelReady(flags) if flags.is_set(AwaitingChannelReadyFlags::OUR_CHANNEL_READY))

lightning/src/ln/channelmanager.rs

@@ -11524,8 +11524,9 @@ where
 					.channel_by_id
 					.iter()
 					.filter(|(_, channel)| channel.context().is_usable())
-					.min_by_key(|(_, channel)| channel.context().channel_creation_height)
-					.and_then(|(_, channel)| channel.funding().get_short_channel_id()),
+					.filter_map(|(_, channel)| channel.as_funded())
+					.min_by_key(|funded_channel| funded_channel.context.channel_creation_height)
+					.and_then(|funded_channel| funded_channel.get_inbound_scid()),
 			})
 			.collect::<Vec<_>>()
 	}