apollo_consensus_orchestrator: avoid cloning the synced block's state diff to compute accessed keys

[gkaempfer]

Summary

Follow-up performance optimization on top of #14962 (merged), which added BlockAccessedKeysData::compute_accessed_keys and wired it into try_sync in sequencer_consensus_context.rs.

In try_sync, computing the accessed keys for a synced block did:

Some(block_data.compute_accessed_keys(&sync_block.state_diff.clone().into()))

This deep-clones the entire ThinStateDiff of the synced block — which can hold thousands of storage/nonce/class-hash entries for a full block — purely to obtain an owned value to convert into a borrowed CommitmentStateDiff. The clone exists only because sync_block is later moved by value into self.deps.batcher.add_sync_block(sync_block, accessed_keys), so the original state diff had to be preserved.

Since From<ThinStateDiff> for CommitmentStateDiff (and the reverse) are cheap field-moves (no allocation) in blockifier::state::cached_state, this PR instead moves the state diff into the CommitmentStateDiff via std::mem::take, computes the accessed keys, and moves it back — avoiding the clone of the block's storage diff on the sync path.

One subtlety: CommitmentStateDiff has no deprecated_declared_classes field (present on ThinStateDiff, used by the state-diff hash and by storage), so that field is carried across the conversion explicitly instead of being silently dropped.

This runs once per synced block height, on the consensus sync path.

Changes

• sequencer_consensus_context.rs: avoid the clone in try_sync, preserving deprecated_declared_classes across the ThinStateDiff ⇄ CommitmentStateDiff round-trip.
• sequencer_consensus_context_test.rs: extended try_sync_forwards_accessed_keys_from_centralized to use a non-empty state diff (including deprecated_declared_classes) and assert add_sync_block receives it unchanged.

Test plan

• cargo build -p apollo_consensus_orchestrator
• SEED=0 cargo test -p apollo_consensus_orchestrator (203 passed)
• cargo clippy -p apollo_consensus_orchestrator --all-targets (clean)
• scripts/rust_fmt.sh
• Reviewed by an Opus subagent; findings addressed (lossy round-trip of deprecated_declared_classes, missing test coverage)

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Generated by Claude Code

[cursor]

PR Summary

Low Risk
Localized sync-path performance and correctness fix with explicit preservation of deprecated class declarations; behavior is covered by an extended unit test.

Overview
On the consensus sync path, when centralized accessed-keys fetching is enabled, try_sync no longer deep-clones the synced block's ThinStateDiff just to call compute_accessed_keys. It mem::takes the diff, converts to CommitmentStateDiff by move, computes keys, then rebuilds ThinStateDiff for add_sync_block.

deprecated_declared_classes is peeled off before conversion and reattached afterward, because CommitmentStateDiff omits that field and a naive round-trip would drop it.

The try_sync_forwards_accessed_keys_from_centralized test now uses a non-empty diff (including deprecated classes) and asserts add_sync_block gets the same state_diff as state sync returned.

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