revert(sync): disable keepalive — causes ChainSync stall in gouroboros

Enabling keepalive fixes the node-side ExceededTimeLimit disconnects but
causes ChainSync to stall after ~2000 blocks due to a gouroboros muxer
interaction between the keepalive and chainsync mini-protocols. This drops
throughput from ~2500 blk/s to ~6 blk/s (300x slower).

Revert to keepalive=false: the node kills us every ~97s but the retry
loop handles reconnects at ~1800 blk/s sustained (~2h full sync).

Co-Authored-By: Claude <noreply@anthropic.com>

Author: wcatz

.gitignore

@@ -29,5 +29,6 @@ duckBot
 vrf.skey
 keys/
 
-# OMP config (local overrides)
+# AI agent config (local only)
+.claude/
 .omp/settings.local.json

sync.go

@@ -18,7 +18,6 @@ import (
 	"github.com/blinklabs-io/gouroboros/ledger/shelley"
 	"github.com/blinklabs-io/gouroboros/protocol/chainsync"
 	pcommon "github.com/blinklabs-io/gouroboros/protocol/common"
-	"github.com/blinklabs-io/gouroboros/protocol/keepalive"
 )
 
 // Shelley intersect points: last Byron block per network.
@@ -87,20 +86,16 @@ func (s *ChainSyncer) Start(ctx context.Context) error {
 	)
 
 	// Connect to node via NtN (required for TCP connections)
-	// Keepalive required: cardano-node's muxer expects keepalive probes from
-	// the client and kills the connection after ~97s of inactivity.
-	// Period=30s sends probes often enough to satisfy the node.
-	// Timeout=90s is generous for response time during heavy ChainSync.
-	keepAliveCfg := keepalive.NewConfig(
-		keepalive.WithPeriod(30*time.Second),
-		keepalive.WithTimeout(90*time.Second),
-	)
+	// Keepalive DISABLED during historical sync: enabling keepalive causes
+	// ChainSync to stall after ~2000 blocks (gouroboros muxer interaction),
+	// dropping throughput from ~2500 blk/s to ~6 blk/s.
+	// Without keepalive the node kills us every ~97s (ExceededTimeLimit),
+	// but the retry loop handles reconnects seamlessly at ~1800 blk/s sustained.
 	errChan := make(chan error, 1)
 	conn, connErr := ouroboros.NewConnection(
 		ouroboros.WithNetworkMagic(uint32(s.networkMagic)),
 		ouroboros.WithNodeToNode(true),
-		ouroboros.WithKeepAlive(true),
-		ouroboros.WithKeepAliveConfig(keepAliveCfg),
+		ouroboros.WithKeepAlive(false),
 		ouroboros.WithChainSyncConfig(chainSyncCfg),
 		ouroboros.WithErrorChan(errChan),
 	)