fix: replace embedded genesis files with authoritative versions from S3

The existing embedded genesis files for pacific-1, atlantic-2, and
arctic-1 were incomplete. Replace them with the authoritative versions
from the sei-testnet-genesis-config S3 bucket and correct the genesis
times in chain metadata.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: bdchatham

chains.go

@@ -23,12 +23,12 @@ var knownChains = map[string]ChainInfo{
 	"pacific-1": {
 		ChainID:     "pacific-1",
 		RPC:         "https://rpc.sei-apis.com",
-		GenesisTime: "2023-05-22T15:00:00Z",
+		GenesisTime: "2023-05-22T15:00:00.000000Z",
 	},
 	"atlantic-2": {
 		ChainID:     "atlantic-2",
 		RPC:         "https://rpc-testnet.sei-apis.com",
-		GenesisTime: "2023-02-24T01:00:00Z",
+		GenesisTime: "2023-02-22T23:45:12.575885043Z",
 	},
 	"arctic-1": {
 		ChainID:     "arctic-1",