feat: port erigontech/rpc-tests into block-aware compare configs

config/compare/erigon/MANIFEST-mainnet.md

@@ -0,0 +1,35 @@
+# Erigon rpc-tests -> json-bench compare (mainnet)
+
+Source: erigontech/rpc-tests (source rpc-tests 214c13799371e832a90d92781f83b0fe2d143d68)
+
+Every test is retargeted to block `latest`, so the whole suite runs on any synced node (no archive dependency).
+
+| config | calls | notes |
+|---|---:|---|
+| `erigon-mainnet.yaml` | 577 | standard methods, compares cleanly across clients |
+| `erigon-mainnet-divergent.yaml` | 337 | informational (noisy cross-client) |
+
+Total runnable: 914
+
+## Dropped (not adaptable to an arbitrary block)
+
+Replay/state addressed only by a fixed hash — no block argument to retarget, and replaying the referenced point needs archive state:
+
+- `debug_getModifiedAccountsByHash` (11)
+- `debug_traceBlockByHash` (10)
+- `debug_traceTransaction` (81)
+- `ots_getInternalOperations` (15)
+- `ots_getTransactionError` (15)
+- `ots_traceTransaction` (22)
+- `trace_replayTransaction` (30)
+- `trace_transaction` (47)
+
+## Run
+
+```bash
+go run ./runner compare --config config/compare/erigon/erigon-mainnet.yaml \
+  --clients config/clients/clients.yaml --client-refs nethermind,geth,reth \
+  --rules config/compare/erigon/erigon-mainnet-rules.yaml
+```
+
+For a moving-head node set `--target-block` to a fixed recent number when regenerating (default `latest` is deterministic across nodes parked at the same head).

config/compare/erigon/README.md

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+# Erigon rpc-tests → json-bench compare
+
+Ported from [`erigontech/rpc-tests`](https://github.com/erigontech/rpc-tests):
+the requests from its `integration/<network>` golden-file suite, converted into
+json-bench `compare` configs. json-bench compare is **differential** (each
+client's response is diffed against the others, not against a golden file), so
+only the requests are ported — the Erigon-captured expected responses are
+dropped. What this adds over hand-written configs is coverage (100+ methods)
+and that **every ported test is runnable on any synced node**.
+
+## Any-block, no archive dependency
+
+The Erigon tests pin specific historical blocks (e.g. `eth_getBalance` at block
+17,000,000), which only an archive node can answer. The importer rewrites every
+test's block reference to a runnable target (`latest` by default), so the whole
+suite runs against a normal synced node:
+
+- block-number / block-tag arguments → the target (`latest`);
+- `eth_getLogs` `fromBlock`/`toBlock` → the target;
+- requests that only *fetch* immutable data by hash (`eth_getBlockByHash`,
+  `eth_getTransactionByHash`, receipts, …) are kept as-is — any full node
+  retains that data;
+- requests that *replay* a fixed point by hash (`trace_transaction`,
+  `debug_traceTransaction`, `debug_traceBlockByHash`, …) have no block argument
+  to retarget and need archive state, so they are **dropped** (listed in
+  `MANIFEST-<network>.md`).
+
+Because compare sends the same request to every client at once, `latest` is
+deterministic when the nodes are parked at the same head. For a moving-head or
+archive node, regenerate with `--target-block <fixed number>`.
+
+## Files
+
+| config | contents |
+|---|---|
+| `erigon-<network>.yaml` | core standard `eth_`/`debug_` methods — compares cleanly across clients |
+| `erigon-<network>-divergent.yaml` | non-standard namespaces / node-local / gas-price-oracle methods (`erigon_`/`ots_`/`parity_`/`engine_`/`admin_`/`txpool_`/`trace_`) — informational, noisy cross-client |
+| `erigon-<network>-rules.yaml` | damps benign cross-client differences (ignore `totalDifficulty`, compare error codes only) — pair with every run |
+
+## Running
+
+```bash
+go run ./runner compare \
+  --config config/compare/erigon/erigon-mainnet.yaml \
+  --clients config/clients/clients.yaml --client-refs nethermind,geth,reth \
+  --rules config/compare/erigon/erigon-mainnet-rules.yaml \
+  --output out/erigon
+```
+
+`-divergent.yaml` is for inspection, not pass/fail.
+
+## Regenerating / updating
+
+```bash
+# fetch the corpus (gitignored) then rewrite the configs
+bash rpc-calls/scripts/generate-erigon-compare/init.sh mainnet
+go run ./rpc-calls/scripts/generate-erigon-compare \
+  --source-ref "$(cat rpc-calls/sources/erigon-rpc-tests/SOURCE_REF)"
+
+# pull a newer corpus
+RPC_TESTS_REF=<sha> bash rpc-calls/scripts/generate-erigon-compare/init.sh mainnet
+```
+
+See [`rpc-calls/scripts/generate-erigon-compare/`](../../../rpc-calls/scripts/generate-erigon-compare)
+for the generator and its flags. The generated files here are checked in so
+they're usable without regenerating.