feat: complete include/exclude observability, fix validation bugs, and organize tests

- Add structured logging for include/exclude operations with comprehensive event tracking
- Fix duplicate counting bug in validation API by eliminating double validation passes
- Simplify color identity validation UX by consolidating into single 'illegal' status
- Organize project structure by moving all test files to centralized code/tests/ directory
- Update documentation reflecting feature completion and production readiness
- Add validation test scripts and performance benchmarks confirming targets met
- Finalize include/exclude feature as production-ready with EDH format compliance

code/tests/test_specific_matches.py

@@ -0,0 +1,60 @@
+#!/usr/bin/env python3
+"""Test improved matching for specific cases that were problematic"""
+
+import requests
+
+# Test the specific cases from the screenshots
+test_cases = [
+    ("lightn", "Should prioritize Lightning Bolt over Blightning/Flight"),
+    ("cahso warp", "Should clearly find Chaos Warp first"),
+    ("bolt", "Should find Lightning Bolt"),
+    ("warp", "Should find Chaos Warp")
+]
+
+for input_text, description in test_cases:
+    print(f"\n🔍 Testing: '{input_text}' ({description})")
+    print("=" * 70)
+    
+    test_data = {
+        "include_cards": input_text,
+        "exclude_cards": "",
+        "commander": "",
+        "enforcement_mode": "warn",
+        "allow_illegal": "false",
+        "fuzzy_matching": "true"
+    }
+    
+    try:
+        response = requests.post(
+            "http://localhost:8080/build/validate/include_exclude",
+            data=test_data,
+            timeout=10
+        )
+        
+        if response.status_code == 200:
+            data = response.json()
+            
+            # Check results
+            if data.get("confirmation_needed"):
+                print("🔄 Confirmation modal would show:")
+                for item in data["confirmation_needed"]:
+                    print(f"   Input: '{item['input']}'")
+                    print(f"   Confidence: {item['confidence']:.1%}")
+                    print(f"   Top suggestions:")
+                    for i, suggestion in enumerate(item['suggestions'][:5], 1):
+                        print(f"     {i}. {suggestion}")
+            elif data.get("includes", {}).get("legal"):
+                fuzzy = data["includes"].get("fuzzy_matches", {})
+                if input_text in fuzzy:
+                    print(f"✅ Auto-accepted: '{input_text}' → '{fuzzy[input_text]}'")
+                else:
+                    print(f"✅ Exact match: {data['includes']['legal']}")
+            else:
+                print("❌ No matches found")
+        else:
+            print(f"❌ HTTP {response.status_code}")
+            
+    except Exception as e:
+        print(f"❌ EXCEPTION: {e}")
+
+print(f"\n💡 Testing complete! Check if Lightning/Chaos suggestions are now prioritized.")