fix(chains/atlantic-2): replace embedded genesis to match live chain

[bdchatham]

Summary

sei-config's embedded chains/atlantic-2/genesis.json didn't match the genesis that the live atlantic-2 chain actually instantiated with. The mismatch was structural — different validator set entirely. This PR replaces the file with the correct content from sei-protocol/chain-configs, plus the populated app_state.params block (cosmosGasParams + feesParams.globalMinimumGasPrices) that the binary requires at cold-start. ChainInfo's hardcoded GenesisTime is updated to match the new file.

Evidence

Cross-checked sei-config's atlantic-2 against the live atlantic-2 chain via an independent operator (sei-testnet-rpc.polkachu.com, at height ~249722485). Polkachu's /genesis_chunked matches chain-configs byte-for-byte on validators, accounts, and balances; sei-config was the outlier.

	top-level .validators	.app_state.bank.balances	.app_state.auth.accounts	.app_state.genutil.gen_txs
sei-config (before)	5	1606	1606	5
chain-configs	17	1043	1043	17
polkachu live atlantic-2	17	1043	1043	17

Validator sets are fundamentally different. validators[0] in array order:

• sei-config (before): 3B9452E7C69E99BB0232E5C17A5C861541D4B766
• chain-configs: C6208FF552C519044DFCA169E88F4EA1A2BE7BAB
• polkachu live: C6208FF552C519044DFCA169E88F4EA1A2BE7BAB ✓

All 17 sorted addresses in chain-configs match all 17 sorted addresses in polkachu (sample of first three: 04AD1DF0..., 1C64B578..., 1E633EC2...). None of sei-config's 5 addresses appear in either set. This isn't drift — it's the wrong genesis entirely.

Why this hasn't been observed in prod

Existing atlantic-2 nodes bootstrap via state-sync, which validates against a recent trusted snapshot and bypasses launch-genesis hash verification. So a node with the wrong embedded genesis can still successfully sync into the right chain. The error mode where this would have surfaced is block-sync-from-genesis (archive bootstrap), where the launch-genesis hash mismatch causes immediate failure. atlantic-2 archives are currently disabled in our prod kustomization for separate reasons, so this drift sat dormant.

Cross-check parity for the other chains (no change needed)

• pacific-1: sei-config matches live chain (validated against sei-rpc.polkachu.com). 25 validators, identical addresses across all three sources (sei-config, chain-configs, polkachu live).
• arctic-1: sei-config matches live chain (validated against rpc-arctic-1.sei-apis.com). 30 validators, identical addresses across all three sources.

Neither pacific-1 nor arctic-1 is touched by this PR.

Changes

1. chains/atlantic-2/genesis.json replaced with chain-configs/atlantic-2/genesis.json (the launch genesis the live chain instantiated with) + the populated app_state.params block. The params block is identical to what pacific-1 and arctic-1 already have in sei-config (added in be978d9 to prevent v6.4.1+ cold-start panics); values pulled from on-chain via seid query params {feesparams,cosmosgasparams} on a running wave-0 RPC. All three chains operationally use 0.020000000000000000 usei and a 1/1 cosmos gas multiplier.

2. chains.go — atlantic-2's ChainInfo.GenesisTime updated from 2023-02-22T23:45:12.575885043Z (the genesis_time of the old wrong copy) to 2023-02-24T01:00:00.000000000Z (the genesis_time the live chain actually has). TestGenesisForChain_KnownChains now passes again.

File-size change: 763 KiB → 521 KiB (the old copy had ~243 KiB of accounts and balances that don't exist in the actual atlantic-2 chain).

What this PR does NOT address

• The arctic-1 archive-bootstrap panic on whitelisted_codehashes_bank_send is a separate binary-version mismatch (v6.5.0 doesn't know that field; the chain runs a newer binary). That field is byte-identical between sei-config and chain-configs for arctic-1, matches what the live chain has, and isn't a genesis drift issue.
• The structural sync mechanism (make sync-genesis + CI drift check) proposed in Sync embedded chain genesis files from sei-protocol/chain-configs #20. The cross-check work for this PR found that 2/3 chains already match upstream; the remaining sync-mechanism need is much smaller than the issue originally framed. Worth a separate refresher comment on Sync embedded chain genesis files from sei-protocol/chain-configs #20.

Follow-ups worth tracking (raised in review, non-blocking)

• Embedded consensus_params vs live consensus_params drift exists on all three chains (missing min_txs_in_block / max_gas_wanted; vote_extensions_enable_height as number vs string). This is the pattern inherited from upstream chain-configs. Only matters for block-sync-from-genesis (state-sync masks it). Worth a follow-up issue documenting the policy: embedded genesis is for state-sync bootstrap only, not replay-from-genesis. Un-defer if anyone proposes a replay flow.
• GenesisTime format normalization: live polkachu reports 2023-02-24T01:00:00Z; embedded file and ChainInfo use 2023-02-24T01:00:00.000000000Z. Future regen scripts would need to normalize. One-line helper as a follow-up.

Refs

• Cross-check methodology: seid query params feesparams against in-cluster wave-0 RPCs + /genesis_chunked against independent operators (polkachu, sei-apis, seinetwork.io).
• Related: Sync embedded chain genesis files from sei-protocol/chain-configs #20 (closes the atlantic-2 portion; broader sync mechanism remains open scope).

[cursor]

PR Summary

Medium Risk
Swaps launch genesis for a production testnet chain, which affects archive/from-genesis bootstrap correctness but not typical state-sync nodes; metadata must stay in sync with the embedded file.

Overview
Replaces the embedded atlantic-2 launch genesis with the version that matches live testnet and upstream chain-configs (17 validators, corrected accounts/balances, plus the required app_state.params block for v6.4.1+ cold-start). Updates chains.go so atlantic-2’s ChainInfo.GenesisTime is 2023-02-24T01:00:00.000000000Z, aligning KnownChain metadata with the new genesis.json and fixing TestGenesisForChain_KnownChains.

pacific-1 and arctic-1 are unchanged.

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