fix: map L1ToL2MessageBundle messages to a fixed-length Noir array

The generated L1ToL2MessageBundle.messages type is a fixed-length (1024) array,
but the bundle's messages field is a plain Fr[], so mapFieldArrayToNoir inferred
length `number` and tsc rejected it (TS2322) at the six block-root mapper call
sites. Pass MAX_L1_TO_L2_MSGS_PER_BLOCK explicitly to produce the fixed length.

Author: spalladino

yarn-project/noir-protocol-circuits-types/src/conversion/server.ts

@@ -12,6 +12,7 @@ import {
   CONTRACT_CLASS_LOG_SIZE_IN_FIELDS,
   FLAT_PUBLIC_LOGS_PAYLOAD_LENGTH,
   MAX_CHECKPOINTS_PER_EPOCH,
+  MAX_L1_TO_L2_MSGS_PER_BLOCK,
   type NULLIFIER_TREE_HEIGHT,
   ULTRA_VK_LENGTH_IN_FIELDS,
 } from '@aztec/constants';
@@ -831,7 +832,9 @@ export function mapRevertCodeToNoir(revertCode: RevertCode): NoirField {
 
 function mapL1ToL2MessageBundleToNoir(bundle: L1ToL2MessageBundle) {
   return {
-    messages: mapFieldArrayToNoir(bundle.messages),
+    // `messages` is a plain `Fr[]` (padded to the cap) rather than a fixed tuple, so pass the length explicitly to
+    // get the fixed-length `FixedLengthArray` the generated `L1ToL2MessageBundle.messages` type requires.
+    messages: mapFieldArrayToNoir(bundle.messages, MAX_L1_TO_L2_MSGS_PER_BLOCK),
     num_msgs: mapNumberToNoir(bundle.numMsgs),
     num_real_msgs: mapNumberToNoir(bundle.numRealMsgs),
   };