Closes #156 - fix: enforce MAX_BATCH_SIZE in all batch functions (#156) test: add b…

[Emmanuel-abiola]

Description

Closes #156

Changes proposed

What were you told to do?

Audit fix: enforce MAX_BATCH_SIZE in all batch functions.

What did I do?

Enforced a batch-size cap in every batch entry point:

• VerifierSlashing.batchSlash — replaced the inline magic number 50 with a named MAX_BATCH_SIZE = 50 constant. Cap kept low because each slash performs an external staking call plus storage writes (heavier per item than a token transfer). Mismatch/oversize/empty cases now revert with custom errors (BatchLengthMismatch, BatchSizeExceeded, EmptyBatch) to match the contract's existing error style.
• TruthBountyClaims.settleClaimsBatch — already enforced MAX_BATCH_SIZE = 200; annotated with the audit reference, no functional change.
• MockReputationOracle.batchSetReputationScores (test mock) — added MAX_BATCH_SIZE = 200 and a size guard for consistency and to prevent confusing out-of-gas failures. This is a robustness change, not a production security fix.

Tests

• Added test/BatchSizeLimit_test.ts covering, per function: empty batch reverts, mismatched array lengths revert, exactly MAX_BATCH_SIZE succeeds, MAX_BATCH_SIZE + 1 reverts.
• Updated the existing array-mismatch assertion in VerifierSlashing_test.ts to expect the new BatchLengthMismatch custom error.

Behavior changes

• batchSlash reverts are now custom errors instead of strings.
• MockReputationOracle.batchSetReputationScores now reverts on empty input (previously a silent no-op); no callers affected.

Check List (Check all the applicable boxes)

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• My code additions will fail neither code linting checks nor unit test.
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