BREAKING CHANGE:
- crate renamed e2e_bench → integration_bench. Run via `cargo run -p integration_bench`.
- env vars removed: LEZ_BEDROCK_BIN, LEZ_BEDROCK_CONFIG_DIR, LEZ_BEDROCK_PORT. Replaced by a docker prerequisite (docker-compose Bedrock via test_fixtures::TestContext).
- output filenames: target/e2e_bench_{dev,prove}.json → target/integration_bench_{dev,prove}.json.
- JSON schema: per-scenario `setup_s` field removed; replaced by run-level `shared_setup_s` (one TestContext is shared across all scenarios in a run).
- internal: bedrock_handle.rs and bench_context.rs deleted; placeholder-string config (PLACEHOLDER_CHAIN_START_TIME) gone.