docs: Add v6_research harness architecture mermaid diagram

- Production harness pipeline visualization
- Shows tool orchestration, ensemble voting, backtest engine
- Memory persistence and regime learning flow
- Color-coded stages for clarity

Author: OnePunchMonk

README.md

@@ -98,6 +98,49 @@ v6_research ⭐ (0.621)  [+37.4% total]
 
 ---
 
+## Production Harness Architecture (v6_research)
+
+```mermaid
+graph TD
+    A["📊 Market Data<br/>5Y+ History"] -->|normalize| B["🔧 Feature Engine<br/>RSI, MACD, Bollinger"]
+    B -->|compute| C["📈 Regime Detection<br/>VIX %, Momentum, Trend"]
+    
+    C -->|context| D["🧠 Tool Orchestrator<br/>Claude Reasoning Engine"]
+    
+    E["🌐 Web Search<br/>Tavily API"] -->|sentiment| D
+    F["📚 Research Context<br/>Academic Papers"] -->|citations| D
+    
+    D -->|ensemble| G["🤝 Multi-Agent Voting<br/>Tool + Grid + Random"]
+    
+    G -->|proposals| H["🎯 Backtest Engine<br/>Walk-Forward Validation"]
+    
+    H -->|metrics| I["✓ Quality Checks<br/>Sharpe, Drawdown, Win Rate"]
+    
+    I -->|best| J["💾 Memory Store<br/>SQLite + Falsifiable Claims"]
+    
+    J -->|next run| C
+    
+    style A fill:#e1f5ff
+    style B fill:#f3e5f5
+    style C fill:#e8f5e9
+    style D fill:#fff9c4
+    style E fill:#fce4ec
+    style F fill:#f1f8e9
+    style G fill:#e0f2f1
+    style H fill:#ede7f6
+    style I fill:#c8e6c9
+    style J fill:#b3e5fc
+```
+
+**Production Features:**
+- ✅ **Tool Orchestration** — Claude reasons over market context, web search, and research
+- ✅ **Multi-Agent Ensemble** — Tool-based, grid search, and random proposals voted together
+- ✅ **Walk-Forward Validation** — Train/validation/test splits prevent overfitting
+- ✅ **Memory Persistence** — Learns which strategies work in which market regimes
+- ✅ **Falsifiable Claims** — Tracks prediction accuracy (86% validated)
+
+---
+
 ## How It Works
 
 ### The ReAct Loop