Fix CI test failures and improve code quality

- Fix account format in tests (4 segments not 5)
- Set test transactions to business hours to reduce time-based risk
- Fix velocity detection test with unique transaction IDs
- Add debug output for validation failures
- All 30 tests now passing
- No clippy warnings

Author: guardsarm

src/fraud_patterns.rs

@@ -393,16 +393,32 @@ mod tests {
             ..Default::default()
         });
 
-        for _ in 0..3 {
-            let txn = create_test_transaction(100.0);
-            let score = detector.calculate_fraud_score(&txn);
-            if detector.get_transaction_count("ACC-123") >= 2 {
-                assert!(score
-                    .flags
-                    .iter()
-                    .any(|f| f.flag_type == FraudFlagType::VelocityExceeded));
-            }
-        }
+        // First transaction - should pass
+        let mut txn1 = create_test_transaction(100.0);
+        txn1.transaction_id = "TXN-VEL-001".to_string();
+        let score1 = detector.calculate_fraud_score(&txn1);
+        assert!(score1
+            .flags
+            .iter()
+            .all(|f| f.flag_type != FraudFlagType::VelocityExceeded));
+
+        // Second transaction - should pass (at limit but not exceeded)
+        let mut txn2 = create_test_transaction(100.0);
+        txn2.transaction_id = "TXN-VEL-002".to_string();
+        let score2 = detector.calculate_fraud_score(&txn2);
+        assert!(score2
+            .flags
+            .iter()
+            .all(|f| f.flag_type != FraudFlagType::VelocityExceeded));
+
+        // Third transaction - should trigger velocity flag (exceeds limit of 2)
+        let mut txn3 = create_test_transaction(100.0);
+        txn3.transaction_id = "TXN-VEL-003".to_string();
+        let score3 = detector.calculate_fraud_score(&txn3);
+        assert!(score3
+            .flags
+            .iter()
+            .any(|f| f.flag_type == FraudFlagType::VelocityExceeded));
     }
 
     #[test]

src/lib.rs

@@ -583,14 +583,22 @@ mod tests {
     use super::*;
 
     fn create_valid_transaction() -> Transaction {
+        // Create timestamp at 12 PM UTC (business hours) to minimize time-based risk
+        let now = Utc::now();
+        let timestamp = now
+            .date_naive()
+            .and_hms_opt(12, 0, 0)
+            .unwrap()
+            .and_utc();
+
         Transaction {
             transaction_id: "TXN-001".to_string(),
             transaction_type: TransactionType::Transfer,
             amount: 1000.0,
             currency: "USD".to_string(),
-            from_account: Some("ACCT-1234-5678-9012-3456".to_string()),
-            to_account: Some("ACCT-6789-0123-4567-8901".to_string()),
-            timestamp: Utc::now(),
+            from_account: Some("ACCT-1234-5678-9012".to_string()),
+            to_account: Some("ACCT-6789-0123-4567".to_string()),
+            timestamp,
             user_id: "USER-001".to_string(),
             metadata: None,
         }
@@ -602,7 +610,15 @@ mod tests {
         let transaction = create_valid_transaction();
         let result = validator.validate(&transaction);
 
-        assert!(result.is_valid);
+        // Debug output
+        if !result.is_valid {
+            eprintln!("Validation failed!");
+            eprintln!("Errors: {:?}", result.errors);
+            eprintln!("Fraud score: {}", result.fraud_score);
+            eprintln!("Risk breakdown: {:?}", result.risk_breakdown);
+        }
+
+        assert!(result.is_valid, "Transaction should be valid. Errors: {:?}, Fraud score: {}", result.errors, result.fraud_score);
         assert!(result.errors.is_empty());
     }