refactor(mev): drop pre-submit simulation in BloxrouteBackrunmeSender.SendBackrunBundle

[datluongductuan]

What

BloxrouteBackrunmeSender.SendBackrunBundle called MevSimulateBundle (simulate_arb_only_bundle) before submitting, and aborted the send if it errored. This drops that pre-submit simulation — SendBackrunBundle now goes straight to submit_arb_only_bundle (with coinbase_profit).

-	// First, simulate the bundle using MevSimulateBundle
-	_, err := s.MevSimulateBundle(ctx, blockNumber, pendingTxHashes[0], txs[0])
-	if err != nil {
-		return SendBundleResponse{}, fmt.Errorf("simulate bundle failed: %w", err)
-	}
-
-	// If simulation passed, proceed with submission
	// Build request params
	params := backrunmeRequestParams{ ... }

Why

The pre-submit simulate round-trip is unnecessary on the send path and adds latency. MevSimulateBundle stays on the type (still part of IBackrunSender) for callers that want to simulate explicitly — only the implicit call inside SendBackrunBundle is removed.

Also resolves the earlier review note that coinbase_profit was carried by submit but not by the in-send simulate: there is no in-send simulate anymore, so the two can't diverge.

Build + vet clean; no signature change.

🤖 Generated with Claude Code