feat: live sync witness cache oracle

[0xOsiris]

PROTO-4718

Creates an optional live witness cache that accumulates pre-image witnesses into a fixed size in memory circular ring buffer. The witnesses can then be fetched over a range externally with enormous compute savings.

As historical witnesses require unwinding the database to the beginning of the range. Witnesses are deterministic based on execution (and the last proven state), and can be easily cached during live sync in the Block Executor minimizing both compute, and complexity of the pre-image witness collection in the proof system.

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Note

Medium Risk
Touches block-import execution via an executor wrapper on the engine validation path; default-off limits blast radius, but enabled mode adds async witness assembly and a new debug RPC surface on proof nodes.

Overview
Introduces an optional live pre-image witness oracle for proof workflows: when --witness.collect is set, the node captures witnesses during normal newPayload import instead of relying on repeated debug_executePayload re-execution.

New world-chain-witness crate defines BlockWitness / RangeWitness and a bounded WitnessCache (depth from --witness.depth, default 1024).

EVM layer: WorldChainEvmConfig is no longer a type alias—it wraps OpEvmConfig with WorldChainBlockExecutorFactory / WorldChainBlockExecutor, which snapshot ExecutionWitnessRecord from the live revm State on executor finish and send BlockExecutionWitness over a channel. A background collector assembles full BlockWitness values (parent state trie, headers, RLP header/txs) into the cache. With collection off, behavior stays a passthrough (no sender). Requires #![feature(min_specialization)] for the State DB witness hook.

Wiring: CLI WitnessArgs, node context creates channel + cache when enabled, WorldChainExecutorBuilder arms the sender, and add-ons spawn the collector and register debug_collectRangeWitness on the debug module when collection is on.

Adds design doc docs/proof/live-preimage-witness-oracle.md. Kona host pre-seeding (design Phase 5) is not included in this diff.

^{Reviewed by Cursor Bugbot for commit 13239c3. Configure here.}

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Benchmark Results

Compared on the same runner in the same workflow run.

group                                                                                              base                                   pr
-----                                                                                              ----                                   --
flashblock_validation_launch_flashblock_sequence_eth_transfers/stream/4fb_x_125tx                  1.00     28.8±0.16ms        ? ?/sec    1.00     28.8±0.16ms        ? ?/sec
flashblock_validation_launch_flashblock_sequence_eth_transfers/stream/4fb_x_250tx                  1.03     57.3±0.25ms        ? ?/sec    1.00     55.9±0.29ms        ? ?/sec
flashblock_validation_launch_flashblock_sequence_eth_transfers/stream/4fb_x_50tx                   1.00     11.9±0.11ms        ? ?/sec    1.00     11.9±0.05ms        ? ?/sec
flashblock_validation_launch_flashblock_sequence_eth_transfers_with_bal/stream/4fb_x_125tx         1.00     35.8±0.34ms        ? ?/sec    1.00     35.8±0.16ms        ? ?/sec
flashblock_validation_launch_flashblock_sequence_eth_transfers_with_bal/stream/4fb_x_250tx         1.02     68.2±0.61ms        ? ?/sec    1.00     67.1±0.30ms        ? ?/sec
flashblock_validation_launch_flashblock_sequence_eth_transfers_with_bal/stream/4fb_x_50tx          1.02     17.4±0.34ms        ? ?/sec    1.00     17.1±0.29ms        ? ?/sec
flashblock_validation_launch_flashblock_sequence_fib/stream/4fb_x_125tx                            1.02     27.1±0.05ms        ? ?/sec    1.00     26.6±0.12ms        ? ?/sec
flashblock_validation_launch_flashblock_sequence_fib/stream/4fb_x_250tx                            1.02     53.1±0.07ms        ? ?/sec    1.00     52.2±0.09ms        ? ?/sec
flashblock_validation_launch_flashblock_sequence_fib/stream/4fb_x_50tx                             1.00     11.2±0.19ms        ? ?/sec    1.00     11.2±0.02ms        ? ?/sec
flashblock_validation_launch_flashblock_sequence_fib_with_bal/stream/4fb_x_125tx                   1.00     34.4±0.19ms        ? ?/sec    1.02     35.0±0.51ms        ? ?/sec
flashblock_validation_launch_flashblock_sequence_fib_with_bal/stream/4fb_x_250tx                   1.00     62.9±0.32ms        ? ?/sec    1.01     63.4±0.40ms        ? ?/sec
flashblock_validation_launch_flashblock_sequence_fib_with_bal/stream/4fb_x_50tx                    1.00     15.9±0.09ms        ? ?/sec    1.01     16.1±0.16ms        ? ?/sec
flashblock_validation_launch_flashblock_sequence_world_id_like_bn254/stream/4fb_x_10tx             1.00    135.1±0.24ms        ? ?/sec    1.00    135.6±0.48ms        ? ?/sec
flashblock_validation_launch_flashblock_sequence_world_id_like_bn254/stream/4fb_x_12tx             1.00    162.0±0.33ms        ? ?/sec    1.00    162.7±0.20ms        ? ?/sec
flashblock_validation_launch_flashblock_sequence_world_id_like_bn254/stream/4fb_x_5tx              1.00     68.2±0.20ms        ? ?/sec    1.00     68.4±0.18ms        ? ?/sec
flashblock_validation_launch_flashblock_sequence_world_id_like_bn254_with_bal/stream/4fb_x_10tx    1.00     22.7±1.11ms        ? ?/sec    1.03     23.3±1.24ms        ? ?/sec
flashblock_validation_launch_flashblock_sequence_world_id_like_bn254_with_bal/stream/4fb_x_12tx    1.00     23.3±0.70ms        ? ?/sec    1.00     23.4±1.01ms        ? ?/sec
flashblock_validation_launch_flashblock_sequence_world_id_like_bn254_with_bal/stream/4fb_x_5tx     1.00     19.2±0.35ms        ? ?/sec    1.01     19.4±0.46ms        ? ?/sec
flashblock_validation_process_flashblock_eth_transfers/txs/1000                                    1.00     48.7±0.15ms        ? ?/sec    1.00     48.6±0.11ms        ? ?/sec
flashblock_validation_process_flashblock_eth_transfers/txs/50                                      1.00      2.6±0.02ms        ? ?/sec    1.01      2.7±0.02ms        ? ?/sec
flashblock_validation_process_flashblock_eth_transfers/txs/500                                     1.00     24.4±0.03ms        ? ?/sec    1.00     24.4±0.03ms        ? ?/sec
flashblock_validation_process_flashblock_eth_transfers_with_bal/txs/1000                           1.00     58.3±0.17ms        ? ?/sec    1.01     58.9±0.19ms        ? ?/sec
flashblock_validation_process_flashblock_eth_transfers_with_bal/txs/50                             1.00      3.8±0.06ms        ? ?/sec    1.01      3.9±0.05ms        ? ?/sec
flashblock_validation_process_flashblock_eth_transfers_with_bal/txs/500                            1.00     29.4±0.09ms        ? ?/sec    1.01     29.5±0.41ms        ? ?/sec
flashblock_validation_process_flashblock_fib/txs/1000                                              1.00     47.8±0.29ms        ? ?/sec    1.00     47.7±0.09ms        ? ?/sec
flashblock_validation_process_flashblock_fib/txs/50                                                1.00      2.5±0.01ms        ? ?/sec    1.01      2.6±0.03ms        ? ?/sec
flashblock_validation_process_flashblock_fib/txs/500                                               1.00     24.0±0.02ms        ? ?/sec    1.00     24.0±0.07ms        ? ?/sec
flashblock_validation_process_flashblock_fib_with_bal/txs/1000                                     1.00     55.4±0.14ms        ? ?/sec    1.00     55.6±0.50ms        ? ?/sec
flashblock_validation_process_flashblock_fib_with_bal/txs/50                                       1.01      3.8±0.04ms        ? ?/sec    1.00      3.7±0.05ms        ? ?/sec
flashblock_validation_process_flashblock_fib_with_bal/txs/500                                      1.00     28.2±0.10ms        ? ?/sec    1.00     28.2±0.13ms        ? ?/sec
flashblock_validation_process_flashblock_world_id_like_bn254/txs/10                                1.00     33.7±0.15ms        ? ?/sec    1.00     33.8±0.06ms        ? ?/sec
flashblock_validation_process_flashblock_world_id_like_bn254/txs/25                                1.00     84.0±0.16ms        ? ?/sec    1.00     84.0±0.06ms        ? ?/sec
flashblock_validation_process_flashblock_world_id_like_bn254/txs/50                                1.00    167.5±0.33ms        ? ?/sec    1.00    167.8±0.14ms        ? ?/sec
flashblock_validation_process_flashblock_world_id_like_bn254_with_bal/txs/10                       1.01      5.7±0.38ms        ? ?/sec    1.00      5.6±0.49ms        ? ?/sec
flashblock_validation_process_flashblock_world_id_like_bn254_with_bal/txs/25                       1.00      8.4±0.10ms        ? ?/sec    1.01      8.5±0.09ms        ? ?/sec
flashblock_validation_process_flashblock_world_id_like_bn254_with_bal/txs/50                       1.19     13.7±1.80ms        ? ?/sec    1.00     11.5±0.10ms        ? ?/sec

Threshold: 10% regression triggers failure

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Cursor Bugbot has reviewed your changes using default effort and found 3 potential issues.

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^{Reviewed by Cursor Bugbot for commit 13239c3. Configure here.}