Modify SubstrateBlockAck as needed

Replaces plan IDs with key + ID, letting the coordinator determine the sessions
for the plans.

Properly scopes which plan IDs are set on which tributaries, and ensures we
have the necessary tributaries at time of handling.

processor/messages/src/lib.rs

@@ -139,9 +139,15 @@ pub mod coordinator {
     }
   }
 
+  #[derive(Clone, PartialEq, Eq, Debug, Zeroize, Encode, Decode, Serialize, Deserialize)]
+  pub struct PlanMeta {
+    pub key: Vec<u8>,
+    pub id: [u8; 32],
+  }
+
   #[derive(Clone, PartialEq, Eq, Debug, Zeroize, Encode, Decode, Serialize, Deserialize)]
   pub enum ProcessorMessage {
-    SubstrateBlockAck { network: NetworkId, block: u64, plans: Vec<[u8; 32]> },
+    SubstrateBlockAck { network: NetworkId, block: u64, plans: Vec<PlanMeta> },
     BatchPreprocess { id: SignId, block: BlockHash, preprocess: Vec<u8> },
     BatchShare { id: SignId, share: [u8; 32] },
   }

processor/src/main.rs

@@ -13,7 +13,7 @@ use serai_client::{
   validator_sets::primitives::{ValidatorSet, KeyPair},
 };
 
-use messages::CoordinatorMessage;
+use messages::{coordinator::PlanMeta, CoordinatorMessage};
 
 use serai_env as env;
 
@@ -344,7 +344,13 @@ async fn handle_coordinator_msg<D: Db, N: Network, Co: Coordinator>(
               .send(messages::coordinator::ProcessorMessage::SubstrateBlockAck {
                 network: N::NETWORK,
                 block: substrate_block,
-                plans: to_sign.iter().map(|signable| signable.1).collect(),
+                plans: to_sign
+                  .iter()
+                  .map(|signable| PlanMeta {
+                    key: signable.0.to_bytes().as_ref().to_vec(),
+                    id: signable.1,
+                  })
+                  .collect(),
               })
               .await;
           }