[forge] Tighter binary classifier: lower threshold + zero failed_weight + larger window

Tunes the existing ProposerAndVoter binary classifier on three axes so it
reliably bans a slow validator instead of leaving it oscillating at the
threshold boundary:

- failure_threshold_percent: 10 -> 5
  V6's injected real failure rate is 10%, exactly at the default threshold.
  Sampling noise pushed it above only ~26-38% of windows. Lowering the
  threshold to 5 makes V6's 10% clearly exceed it under any window size.

- failed_weight: 1 -> 0
  When a validator IS classified failed, it currently keeps a tiny weight
  (1 vs active 1000), still leaking ~1/N share. Setting to 0 fully excludes.

- proposer_window_num_validators_multiplier: 10 -> 50
  Larger observation window reduces variance in the failure-rate estimate,
  so classification flips less and is more decisive when it does.

No heuristic changes. Stacks on baseline #19330.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: danielxiangzl

testsuite/forge-cli/src/suites/realistic_environment.rs

@@ -20,8 +20,9 @@ use aptos_forge::{
     TransactionType,
 };
 use aptos_sdk::types::on_chain_config::{
-    BlockGasLimitType, FeatureFlag, Features, OnChainChunkyDKGConfig, OnChainConsensusConfig,
-    OnChainExecutionConfig, OnChainRandomnessConfig, TransactionShufflerType,
+    BlockGasLimitType, ConsensusAlgorithmConfig, FeatureFlag, Features, LeaderReputationType,
+    OnChainChunkyDKGConfig, OnChainConsensusConfig, OnChainExecutionConfig, OnChainRandomnessConfig,
+    ProposerAndVoterConfig, ProposerElectionType, TransactionShufflerType,
 };
 use aptos_testcases::{
     load_vs_perf_benchmark::{LoadVsPerfBenchmark, TransactionWorkload, Workloads},
@@ -452,9 +453,36 @@ pub(crate) fn realistic_env_max_load_test(
         .with_genesis_helm_config_fn(Arc::new(move |helm_values| {
             // No epoch change so measurements are stable.
             helm_values["chain"]["epoch_duration_secs"] = (24 * 3600).into();
+            // Tighter binary classifier for slow leaders:
+            // - failure_threshold_percent: 10 -> 5 so a validator with a true 10%
+            //   failure rate clearly exceeds the threshold (instead of sitting on
+            //   the boundary, which causes oscillation between active/failed under
+            //   sampling noise).
+            // - failed_weight: 1 -> 0 so a validator classified failed is excluded
+            //   entirely from leader selection instead of leaking 1/N share.
+            // - proposer_window_num_validators_multiplier: 10 -> 50 so the larger
+            //   observation window stabilizes the failure-rate estimate.
+            let mut consensus_config = OnChainConsensusConfig::default_for_genesis();
+            if let OnChainConsensusConfig::V5 {
+                alg: ConsensusAlgorithmConfig::JolteonV2 { ref mut main, .. },
+                ..
+            } = consensus_config
+            {
+                main.proposer_election_type = ProposerElectionType::LeaderReputation(
+                    LeaderReputationType::ProposerAndVoterV2(ProposerAndVoterConfig {
+                        active_weight: 1000,
+                        inactive_weight: 10,
+                        failed_weight: 0,           // bumped from 1: classified-failed -> banned
+                        failure_threshold_percent: 5, // bumped from 10: clear of V6's true 10%
+                        proposer_window_num_validators_multiplier: 50, // bumped from 10
+                        voter_window_num_validators_multiplier: 1,
+                        weight_by_voting_power: true,
+                        use_history_from_previous_epoch_max_count: 5,
+                    }),
+                );
+            }
             helm_values["chain"]["on_chain_consensus_config"] =
-                serde_yaml::to_value(OnChainConsensusConfig::default_for_genesis())
-                    .expect("must serialize");
+                serde_yaml::to_value(consensus_config).expect("must serialize");
             helm_values["chain"]["on_chain_execution_config"] =
                 serde_yaml::to_value(OnChainExecutionConfig::default_for_genesis())
                     .expect("must serialize");