fix: catch exceptions in ChonkBatchVerifier::batch_check (#22270)

## Summary

PR #22263 replaced `BB_ASSERT(val.on_curve())` with `throw_or_abort()`
in `field_conversion.hpp` for the external audit response. This bypasses
`BB_DISABLE_ASSERTS()` and causes
`ChonkBatchVerifierTests.RandomMixedBatches` to crash when deserializing
corrupted IPA proof points during `batch_check()`.

Added try-catch in `batch_check()` so exceptions from corrupted proof
data return `false` (triggering bisection) instead of terminating the
process. This is consistent with the existing try-catch in
`parallel_reduce()`.

All 29 chonk tests pass.

Full analysis:
https://gist.github.com/AztecBot/71089def650112d95757a7d3af6c0d67

ClaudeBox log: https://claudebox.work/s/fd385651d6fa6262?run=1

Author: AztecBot

barretenberg/cpp/src/barretenberg/chonk/chonk_batch_verifier.cpp

@@ -216,18 +216,23 @@ bool ChonkBatchVerifier::batch_check(const std::vector<ReduceResult>& results, c
 
     set_parallel_for_concurrency(num_cores_);
 
-    // Collect IPA claims and transcripts for batch verification
-    std::vector<OpeningClaim<curve::Grumpkin>> claims;
-    std::vector<std::shared_ptr<NativeTranscript>> transcripts;
-    claims.reserve(indices.size());
-    transcripts.reserve(indices.size());
-    for (size_t idx : indices) {
-        claims.push_back(results[idx].ipa_claim);
-        transcripts.push_back(std::make_shared<NativeTranscript>(results[idx].ipa_proof));
-    }
+    try {
+        // Collect IPA claims and transcripts for batch verification
+        std::vector<OpeningClaim<curve::Grumpkin>> claims;
+        std::vector<std::shared_ptr<NativeTranscript>> transcripts;
+        claims.reserve(indices.size());
+        transcripts.reserve(indices.size());
+        for (size_t idx : indices) {
+            claims.push_back(results[idx].ipa_claim);
+            transcripts.push_back(std::make_shared<NativeTranscript>(results[idx].ipa_proof));
+        }
 
-    auto ipa_vk = VerifierCommitmentKey<curve::Grumpkin>{ ECCVMFlavor::ECCVM_FIXED_SIZE };
-    return IPA<curve::Grumpkin>::batch_reduce_verify(ipa_vk, claims, transcripts);
+        auto ipa_vk = VerifierCommitmentKey<curve::Grumpkin>{ ECCVMFlavor::ECCVM_FIXED_SIZE };
+        return IPA<curve::Grumpkin>::batch_reduce_verify(ipa_vk, claims, transcripts);
+    } catch (const std::exception& e) {
+        info("ChonkBatchVerifier: batch_check exception: ", e.what());
+        return false;
+    }
 }
 
 void ChonkBatchVerifier::bisect(std::vector<ReduceResult>& results,