feat: wall clock timestamps, committee BFT, emission fix, duplicate node fix

Emission fix (lazy_rewards.rs, node.rs):
- Add sentinel guard in calculate_years_since_genesis: genesis_timestamp==0 returns 0
  Prevents 56-year miscalculation causing 14 halvings and 3 QNC instead of 251k QNC
- Add update_genesis_timestamp() method to PhaseAwareRewardManager
- Call update_genesis_timestamp at 4 critical points: genesis creation, network sync,
  P2P receive, and storage load on restart

Committee-based BFT (block.rs, node.rs):
- Add consensus_committee field Option<Vec<String>> to ConsensusData struct with serde default
- Implement select_consensus_committee() using SHA3 VRF seeded from MacroBlock N-2 randomness_beacon
- CONSENSUS_COMMITTEE_SIZE=100, COMMITTEE_THRESHOLD=120
- trigger_macroblock_consensus: subsample committee when total validators exceed threshold
- start_macroblock_consensus_listener: non-committee validators skip BFT and receive MB via sync
- Emergency macroblocks bypass committee (consensus_committee=None)
- Scales MacroBlock BFT from O(n^2) to O(1) for networks up to 1000+ validators

Wall clock timestamps (node.rs):
- Replace slot-based timestamps (genesis_ts + height * 1s) with SystemTime::now()
  Old approach accumulated 20min drift per 8h, compounding to days and months over time
- MicroBlock: timestamp = max(now(), parent.timestamp + 1) guarantees strict monotonicity
- Emergency MacroBlock: timestamp = now() with defensive genesis existence guard
- Consensus MacroBlock: timestamp = now()
- Validation updated to Ethereum-style rules only: future (<=now+15s) and monotonicity (>parent.ts)
- Remove slot-based past check to ensure rolling update compatibility across mixed-version networks
- TIMESTAMP_FUTURE_TOLERANCE raised from 5s to 15s matching Ethereum standard
- Explorer will now show correct relative times for all new transactions

Duplicate node registration fix (node.rs):
- Prevent same wallet address from registering a Light or Super node more than once on-chain

Made-with: Cursor

Author: AIQnetLab

core/qnet-consensus/src/lazy_rewards.rs

@@ -270,14 +270,21 @@ impl PhaseAwareRewardManager {
             .duration_since(UNIX_EPOCH)
             .unwrap_or_default()
             .as_secs();
-            
+
+        // CRITICAL: genesis_timestamp=0 means genesis block not yet received (sentinel).
+        // In that case return 0 (year 0 = no halving = full emission).
+        // Without this guard, unix_epoch(0) as genesis gives ~56 years → 14 halvings → 3 QNC instead of 251k QNC.
+        if self.genesis_timestamp == 0 {
+            return 0;
+        }
+
         if now > self.genesis_timestamp {
             (now - self.genesis_timestamp) / (365 * 24 * 60 * 60)
         } else {
             0
         }
     }
-    
+
     /// Calculate dynamic Pool 1 base emission with sharp drop halving
     fn calculate_pool1_base_emission(&self) -> u64 {
         let years_since_genesis = self.calculate_years_since_genesis();
@@ -576,6 +583,16 @@ impl PhaseAwareRewardManager {
     pub fn get_genesis_timestamp(&self) -> u64 {
         self.genesis_timestamp
     }
+
+    /// Update genesis timestamp (called when genesis block is received from network)
+    /// CRITICAL: Must be called whenever GLOBAL_GENESIS_TIMESTAMP is set to non-zero value,
+    /// otherwise calculate_pool1_base_emission() uses unix_epoch as genesis → years=56 → wrong halving
+    pub fn update_genesis_timestamp(&mut self, ts: u64) {
+        if ts > 0 && ts != self.genesis_timestamp {
+            println!("[INFO][REWARDS] genesis_ts_updated old={} new={}", self.genesis_timestamp, ts);
+            self.genesis_timestamp = ts;
+        }
+    }
 
     /// Get Pool #2 transaction fees accumulated
     pub fn get_pool2_fees(&self) -> u64 {

core/qnet-state/src/block.rs

@@ -219,6 +219,18 @@ pub struct ConsensusData {
     #[serde(default)]
     pub pool2_total_fees: Option<u64>,
 
+    // ═══════════════════════════════════════════════════════════════════════════
+    // COMMITTEE-BASED BFT (v3.36)
+    // VRF-subsampled committee for scalable MacroBlock consensus (up to 1000+ validators)
+    // ═══════════════════════════════════════════════════════════════════════════
+
+    /// Committee members selected for this MacroBlock's BFT consensus
+    /// When total validators > COMMITTEE_THRESHOLD, a VRF-subsampled committee
+    /// of COMMITTEE_SIZE nodes handles commit-reveal. Other nodes accept the result.
+    /// Format: sorted Vec<String> of node_ids
+    #[serde(default)]
+    pub consensus_committee: Option<Vec<String>>,
+
     /// Pool 3: Total activation QNC collected in this emission window (Phase 2 only)
     /// Recorded ONLY in EMISSION MacroBlocks when Phase 2 is active
     /// Distribution: Equal share to ALL eligible nodes (Light + Full + Super)