experiment: combine batch proof verification (#1872), tx revalidation cache (#744) and live intra-block ledger states (#2050)

Batch-Implemenation-Plan-Prompt.md

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+❯ Let's create an implementation plan for the batch verification work
+
+  read the current notes
+
+  My thinking:
+
+  - let's create a large LRU cache in our ledger/ crate - this cache will live on the native side of the node, and will be large (1000?) - mapping <tx-hashes> -> <proof-verification-result:bool>
+    - we don't want this cache to miss - a cache miss should result in an error log (since it represents potentially pretty slow block production/verification)
+
+  - Let's leave the batch verification implementation open for now - just know that this is the API we'll use for the ledger:
+  ```
+  // Pass defer_proofs() so Transaction::well_formed skips inline verification.
+  let deferred = WellFormedStrictness::default().defer_proofs();
+  let mut all_evidence = vec![];
+  for tx in &block_transactions {
+      tx.well_formed(ref_state, deferred, tblock)?;
+      all_evidence.extend(tx.collect_proof_evidence(ref_state)?);
+  }
+  // One batch verify covers contract + dust + zswap proofs for the entire block.
+  P::batch_proof_verify(&all_evidence, deferred.proof_verification_mode)?;
+  ```
+
+  We should compute this on mempool entry (let's abstract into a func with a todo!() implementation for now, but focus instead on the data flow) and on block import
+
+  On mempool entry, we should use the algorithm in the notes, and create a custom implementation of ChainApi to feed this queue. The VerifiedTransaction returned from well_formed() should be added to the tx validation cache (soft and strict) once the proofs have been verified. We should add a `todo!()` function for the fallback if batch proof verification fails
+
+  For block import, let's create a BlockImport wrapper as indicated by the notes. Block import will first do all the wellformed checks with deffered proofs, then attempt to batch-verify the proofs. There is no fallback for block import - if block import fails, that's it.
+
+  Whenever a transaction is being processed, it should check the proof-verified cache. If there is a cache miss, this is an error log (the cache should always be filled, either when a block is imported, or a tx is entering the mempool)
+
+  The exception to this is the ingress points, in the mempool and in block import. These points should not poll the proof-verification or tx-validation caches.
+
+  Create an implementation plan based on this