#### 2. パフォーマンス改善
```python
# PR内のコード
def process_images(image_list):
    results = []
    for img in image_list:
        processed = cv2.resize(img, (224, 224))
        results.append(processed)
    return results

# Copilotのコメント
"""
⚡ Performance: リスト内包表記またはNumPy配列の事前割り当てを使用すると
パフォーマンスが向上する可能性があります。

Suggested optimization:
```python
def process_images(image_list):
    return [cv2.resize(img, (224, 224)) for img in image_list]
    
# または大量の画像の場合:
def process_images_batch(image_list):
    results = np.empty((len(image_list), 224, 224, 3), dtype=np.uint8)
    for i, img in enumerate(image_list):
        results[i] = cv2.resize(img, (224, 224))
    return results

#### 3. コードスタイル
```python
# PR内のコード
def calculate_metrics(y_true,y_pred,threshold = 0.5):
    tp=np.sum((y_true==1)&(y_pred>=threshold))
    return tp

# Copilotのコメント
"""
📝 Style: PEP 8準拠のためのフォーマット改善を推奨します。

Suggested style improvements:
```python
def calculate_metrics(y_true, y_pred, threshold=0.5):
    """Calculate true positives for binary classification."""
    tp = np.sum((y_true == 1) & (y_pred >= threshold))
    return tp

#### 2. 認証・認可の問題
```python
# 脆弱なコード
@app.route('/admin/users')
def admin_users():
    return render_template('admin_users.html', users=get_all_users())

# Copilotの警告
"""
⚠️ WARNING: Missing authentication check
This endpoint appears to be administrative but lacks authentication.

Suggested fix:
```python
@app.route('/admin/users')
@require_auth
@require_role('admin')
def admin_users():
    return render_template('admin_users.html', users=get_all_users())

#### 3. 機密情報の露出
```python
# 脆弱なコード
logger.info(f"User login attempt: {username}, password: {password}")

# Copilotの警告
"""
🔐 SECURITY: Sensitive information in logs
Passwords should never be logged, even for debugging.

Secure approach:
```python
logger.info(f"User login attempt: {username}")
# パスワードは記録しない

### セキュリティレポートの活用

#### PRセキュリティサマリー
```markdown
## Security Review Summary

### 🔍 Scan Results
- **Critical**: 0
- **High**: 1
- **Medium**: 3
- **Low**: 5

### 📊 Details

#### High Severity
1. **Insufficient Input Validation** (line 45)
   - User input not sanitized before use
   - Potential XSS vulnerability

#### Medium Severity
1. **Weak Cryptography** (line 120)
   - MD5 used for password hashing
   - Recommend bcrypt or argon2
   
2. **Missing CSRF Protection** (line 200)
   - Form submission lacks CSRF token
   
3. **Insecure Deserialization** (line 350)
   - pickle.loads() used on user input

### ✅ Recommendations
1. Implement input validation library
2. Update to secure hashing algorithm
3. Add CSRF middleware
4. Use JSON instead of pickle