feat(seidb): Add JSON output to evm-logical-digest and inspect a FlatKV migration in flight

CHANGELOG.md

@@ -31,6 +31,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 ## Unreleased
 
 ### Improvements
+* [#4166](https://github.com/sei-protocol/sei-chain/pull/4166) feat(seidb): `evm-logical-digest` can emit both digest and inspect reports as one JSON object on stdout, while progress and warnings go to stderr. Inspect mode now supports the mid-migration composite EVM view and semantic memiavl replay, so operators can shard and locate mismatched EVM keys during a FlatKV drain. Digest replay opens memiavl read-only without changelog repair, so an observer cannot truncate a live node's changelog. `seidb` now reports a failing command on stderr rather than stdout, so a refused `--json` run leaves stdout empty instead of putting a bare error line where the report belongs.
 * [#4009](https://github.com/sei-protocol/sei-chain/pull/4009) Bound `/store/*/subspace` ABCI queries with pair/byte caps, empty-prefix rejection, SS-path concurrency limits, and context-aware iteration to prevent memory-exhaustion DoS.
 * [#4032](https://github.com/sei-protocol/sei-chain/pull/4032) fix(config): the default `telemetry.prometheus-retention-time` drops from `7200` to `0`, so neither app.toml-generation pipeline (`seid init`, or the file a node writes for itself on any other subcommand) starts the Prometheus metrics sink unless an operator sets a positive retention. Freshly generated nodes keep the bounded in-memory telemetry sink used by SIGUSR1 dumps. Existing `app.toml` files are unchanged.
 * [#4021](https://github.com/sei-protocol/sei-chain/pull/4021) feat(grpc): per-IP rate-limit admission for the gRPC plane, off by default behind `[grpc] rate-limiting-enabled` (new `ip-rate-limit-rps` / `ip-rate-limit-burst` / `trusted-proxy-cidrs`, defaults 10 rps / 20 burst / trust no proxy). Native gRPC (:9090) is admitted by a tap handler and gRPC-Web (:9091) by HTTP middleware, both before the request is protobuf-decoded, so a throttled caller cannot spend the decoder; streams pay one token to establish and one per inbound message. Both planes draw from the same per-IP buckets. Over-budget callers get `ResourceExhausted` on :9090 and HTTP 429 on :9091, counted by `rpc_rate_limit_rejected_total{plane="grpc", method_namespace}`.

sei-db/tools/cmd/seidb/main.go

@@ -34,7 +34,9 @@ func main() {
 		operations.EvmLogicalDigestCmd(),
 		operations.HashLogCmd())
 	if err := rootCmd.Execute(); err != nil {
-		fmt.Println(err)
+		// Subcommands with a --json mode make stdout a machine-readable channel, so a
+		// bare error line there would corrupt the report a caller is parsing.
+		fmt.Fprintln(os.Stderr, err)
 		os.Exit(1)
 	}
 }