docs: snowball → Quasar/Wave terminology (no code changes)

Follow-up docs cleanup from the snow-removal audit — these two files
still referenced 'snowball configuration' and 'Snowball' engine names
even though the consensus code itself is 100% Quasar family. Aligns
docs with the code.

engine/chain/ERROR_TESTS_SUMMARY.md

@@ -26,7 +26,7 @@ Successfully ported error propagation tests from upstream chain consensus to Lux
 - **ErrorBlock** - Test block implementation that can inject errors on Accept/Reject/Verify
 - **Consensus** - Simplified consensus engine for testing with proper error propagation
 - **ConsensusContext** - Context with Prometheus registerer for metrics testing
-- **Parameters** - Consensus parameters matching snowball configuration
+- **Parameters** - Consensus parameters matching Quasar/Wave configuration
 
 ### Adaptations from upstream
 1. Used Lux's `bag.Bag` from `node/utils/bag` instead of upstream's bag implementation

pkg/README.md

@@ -75,14 +75,14 @@ make test-cpp
 
 ## Consensus Engines
 
-All implementations support these consensus engines:
+All implementations support these consensus engines (Quasar family):
 
-1. **Snowball** - Classic Byzantine fault-tolerant consensus
-2. **Avalanche** - DAG-based consensus with conflict sets
-3. **Snowflake** - Simplified binary consensus
-4. **DAG** - Full directed acyclic graph consensus
+1. **Wave** - Threshold voting with fast probabilistic consensus (production)
+2. **Nova** - Linear chain consensus (wraps Ray sub-protocol)
+3. **Nebula** - DAG consensus with safe-prefix commit (wraps Field sub-protocol)
+4. **PostQuantum** - Quantum-resistant consensus with BLS + Corona + ML-DSA
 5. **Chain** - Linear chain consensus for ordered blocks
-6. **PostQuantum** - Quantum-resistant consensus with lattice cryptography
+6. **DAG** - Full directed acyclic graph consensus
 
 ## Performance Benchmarks