feat(stm): add recursive IVC circuit benchmarks

[hjeljeli32]

Content

This PR adds benchmarks for the recursive IVC circuit's prover, verifier, off-circuit accumulator fold, and setup. They are driven end-to-end by a thin benchmark-internals-gated façade that delegates to the production IVC proof-system code, so the measured operations are the same code paths run in production. The inner circuit is the small committed (degree-13) non-recursive certificate, sourced from the committed golden assets plus one additive genesis fixture, and every transition path (genesis, same-epoch, next-epoch) is covered.

Each run builds the shared recursive setup once (a full keygen) and reports single-observation timings in consolidated tables. Given a degree-19 recursive proof costs tens of seconds and the keygen runs for minutes, Criterion's sampling is not used (mirroring the existing halo2_prover_modes bench).

Changes

• Benchmark harness: new mithril-stm/benches/ivc_halo2_snark.rs (gated behind future_snark and
  benchmark-internals), a single-observation report driven by the IvcBenchEnv façade. One shared keygen
  per run; a per-path prove/verify/fold table and a setup cold-vs-warm table.
• Asset layer / fixtures: moved the read-only IVC asset layer out of the test tree (embedded_assets)
  so benchmarks and tests can share it, and added one additive genesis benchmark fixture. Existing golden
  assets are unchanged.
• Measured operations: recursive prover (create_proof, Poseidon and Blake2b transcripts); verification
  as both the isolated KZG opening and the full verification (opening plus the folded-accumulator check); the
  off-circuit accumulator fold per transition path (genesis is an accumulator passthrough, so it has no fold);
  and setup cold vs warm, measured separately for the SRS and for the certificate + recursive circuit keys.
• Façade: added a warm-start SRS load through the production cached read path with the same downsize as
  production setup, symmetric cold_start/warm_start naming, and a measure_keys that mirrors production
  setup (certificate verifying key then recursive key pair) so cold and warm cover the same key layers.
• CLI: a fail-closed argument parser (in a benchmark-internals-gated bench_cli module, unit-tested) —
  --list to print the ids, an optional single literal id/prefix filter, and rejection of anything that
  could otherwise trigger an accidental multi-minute keygen (e.g. value-taking options, --test,
  --profile-time, regex filters).

Pre-submit checklist

• Branch
  • Tests are provided (if possible)
  • Crates versions are updated (if relevant)
  • CHANGELOG file is updated (if relevant)
  • Commit sequence broadly makes sense
  • Key commits have useful messages
• PR
  • All check jobs of the CI have succeeded
  • Self-reviewed the diff
  • Useful pull request description
  • Reviewer requested
• Documentation
  • No new TODOs introduced

Issue(s)

Closes #3412

[github-actions]

Test Results

     5 files  ± 0     209 suites  ±0   1h 49m 38s ⏱️ - 1h 16m 34s
 3 345 tests  - 41   3 345 ✅  - 41  0 💤 ±0  0 ❌ ±0 
11 080 runs   - 41  11 080 ✅  - 41  0 💤 ±0  0 ❌ ±0 

Results for commit 8d57eda. ± Comparison against base commit 936eadd.

This pull request removes 51 and adds 10 tests. Note that renamed tests count towards both.

mithril-stm ‑ circuits::halo2::tests::golden::cases::negative::slow::index_out_of_bounds
mithril-stm ‑ circuits::halo2::tests::golden::cases::negative::slow::index_too_large_for_circuit_range
mithril-stm ‑ circuits::halo2::tests::golden::cases::negative::slow::indices_not_increasing
mithril-stm ‑ circuits::halo2::tests::golden::cases::negative::slow::leaf_merkle_path_mismatch
mithril-stm ‑ circuits::halo2::tests::golden::cases::negative::slow::leaf_swap_keep_merkle_path
mithril-stm ‑ circuits::halo2::tests::golden::cases::negative::slow::leaf_wrong_verification_key
mithril-stm ‑ circuits::halo2::tests::golden::cases::negative::slow::merkle_path_corrupt_sibling
mithril-stm ‑ circuits::halo2::tests::golden::cases::negative::slow::merkle_path_flip_position
mithril-stm ‑ circuits::halo2::tests::golden::cases::negative::slow::merkle_path_length_long
mithril-stm ‑ circuits::halo2::tests::golden::cases::negative::slow::merkle_path_length_short
…

mithril-stm ‑ circuits::halo2_ivc::bench_cli::tests::a_single_literal_filter_is_kept
mithril-stm ‑ circuits::halo2_ivc::bench_cli::tests::control_flags_map_to_their_variants
mithril-stm ‑ circuits::halo2_ivc::bench_cli::tests::help_and_version_take_precedence_over_control_flags
mithril-stm ‑ circuits::halo2_ivc::bench_cli::tests::no_args_runs_everything
mithril-stm ‑ circuits::halo2_ivc::bench_cli::tests::tolerated_valueless_flags_do_not_disturb_parsing
mithril-stm ‑ circuits::halo2_ivc::bench_cli::tests::unsupported_and_malformed_inputs_are_rejected
mithril-stm ‑ circuits::halo2_ivc::bench_cli::tests::value_taking_options_are_rejected_not_swallowed
mithril-stm ‑ circuits::halo2_ivc::tests::golden::positive::genesis_benchmark_fixture_is_deterministic_and_valid
mithril-stm ‑ protocol::key_registration::register::tests::register_by_entry_rejects_same_snark_key_with_different_concatenation_key
mithril-stm ‑ protocol::key_registration::register::tests::register_by_entry_rejects_same_verification_key_with_different_stake

♻️ This comment has been updated with latest results.

[Copilot]

Pull request overview

This PR introduces an end-to-end benchmark suite for the recursive IVC Halo2 SNARK in mithril-stm, driven through a benchmark-internals-gated façade that delegates to the production proof-system paths. It also refactors the IVC golden-asset layer so both tests and benchmarks can share the same embedded fixtures, and adds a deterministic genesis benchmark fixture plus a fail-closed benchmark CLI filter.

Changes:

• Add a new ivc_halo2_snark benchmark target with manual single-observation timing tables and a fail-closed CLI filter.
• Move the read-only embedded golden-asset decoding into a shared embedded_assets module and add an additive genesis benchmark fixture (plus a test to guard determinism/validity).
• Expose a small set of internal APIs under benchmark-internals to reuse production setup/prove/verify/fold code paths in benchmarks.

Reviewed changes

Copilot reviewed 16 out of 17 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
mithril-stm/src/proof_system/ivc_halo2_snark/verifier_setup.rs	Extends test-only verifier-setup constructor gating to benchmarks.
mithril-stm/src/proof_system/ivc_halo2_snark/proof.rs	Makes transcript-based proving helper accessible to the benchmark façade.
mithril-stm/src/proof_system/ivc_halo2_snark/mod.rs	Re-exports IvcProverInput for benchmarks/tests.
mithril-stm/src/circuits/trusted_setup.rs	Exposes unsafe-SRS helpers to benchmarks (previously tests only).
mithril-stm/src/circuits/halo2_ivc/types.rs	Allows test helper conversion (from_field) for benchmarks.
mithril-stm/src/circuits/halo2_ivc/tests/golden/positive.rs	Adds a determinism/validity guard test for the new genesis benchmark fixture.
mithril-stm/src/circuits/halo2_ivc/tests/common/generators/setup.rs	Adds filesystem path for the additive genesis benchmark fixture asset.
mithril-stm/src/circuits/halo2_ivc/tests/common/generators/asset_generation.rs	Adds generator + ignored entrypoint to produce the benchmark fixture asset.
mithril-stm/src/circuits/halo2_ivc/tests/common/field_encoding.rs	Re-exports field-encoding helper from the shared embedded asset layer.
mithril-stm/src/circuits/halo2_ivc/tests/common/asset_readers.rs	Keeps test-only asset writers; re-exports shared embedded loaders/types.
mithril-stm/src/circuits/halo2_ivc/mod.rs	Wires in benchmark-only modules and the shared embedded asset module.
mithril-stm/src/circuits/halo2_ivc/embedded_assets.rs	New shared read-only embedded asset layer (types + decoders + include_bytes!).
mithril-stm/src/circuits/halo2_ivc/bench_helpers.rs	New benchmark façade building setup/fixtures and delegating to production code paths.
mithril-stm/src/circuits/halo2_ivc/bench_cli.rs	New fail-closed CLI parser (unit-tested) for benchmark filtering.
mithril-stm/Cargo.toml	Registers the new ivc_halo2_snark benchmark with required features.
mithril-stm/benches/ivc_halo2_snark.rs	New benchmark harness producing consolidated timing tables (manual timing).

Comments suppressed due to low confidence (1)

mithril-stm/src/circuits/trusted_setup.rs:212

• TrustedSetupProvider::with_unsafe_srs now compiles under feature = "benchmark-internals", but it still uses multiple unwrap() calls for serialization and filesystem IO. This can panic during benchmark runs (e.g. permission / disk full / temp dir issues) and also violates the project’s “no unwrap outside tests” guideline. Consider returning StmResult<Self> and propagating errors with ? (and Context) instead of panicking.

        let mut srs_bytes = Vec::new();
        srs.write_custom(&mut srs_bytes, SerdeFormat::RawBytes).unwrap();

        let srs_dir = base_dir.join(MITHRIL_CIRCUIT_SRS_FOLDER);
        create_dir_all(&srs_dir).unwrap();