🔐 RESTORE: Admin password reset functionality

✅ Added admin password reset capability with:
   - Generate secure temporary passwords (12 chars with symbols)
   - Create password reset links with 15-min expiry
   - Beautiful modal UI with copy-to-clipboard functionality
   - Toggle password visibility for security
   - Reset buttons in both users list and user detail pages
   - Proper error handling and loading states
   - Responsive design for mobile/desktop

FEATURES:
- Admins can reset any user's password instantly
- Users get both temporary password and reset link options
- Secure password generation with proper entropy
- Audit logging of all password reset actions
- Professional UI with Bootstrap modals and tooltips

SAFE: Only affects admin functionality, calculator unchanged

src/app/routes/admin.py

@@ -478,6 +478,52 @@ def reset_cost_factors():
         flash('An error occurred while resetting cost factors.', 'error')
         return redirect(url_for('admin.cost_factors'))
 
+@bp.route('/user/<int:user_id>/reset-password', methods=['POST'])
+@login_required
+@limiter.limit("10 per minute")
+def admin_reset_password(user_id):
+    """Admin function to reset a user's password"""
+    try:
+        user = User.query.get_or_404(user_id)
+        
+        # Generate a temporary password
+        import secrets
+        import string
+        
+        # Generate a secure temporary password (12 characters with mix of letters, numbers, symbols)
+        temp_password = ''.join(secrets.choice(string.ascii_letters + string.digits + '!@#$%^&*') for _ in range(12))
+        
+        # Set the new password
+        user.set_password(temp_password)
+        
+        # Generate a reset token for the user (optional - they can use this to set their own password)
+        reset_token = user.generate_reset_token()
+        
+        db.session.commit()
+        
+        # Log the password reset
+        current_app.logger.info(f'Admin {current_user.email} reset password for user {user.email}')
+        
+        # Create reset URL
+        reset_url = url_for('auth.reset_password', token=reset_token, _external=True)
+        
+        return jsonify({
+            'status': 'success',
+            'message': 'Password reset successfully',
+            'temporary_password': temp_password,
+            'reset_url': reset_url,
+            'username': user.username,
+            'email': user.email
+        })
+        
+    except Exception as e:
+        db.session.rollback()
+        current_app.logger.error(f'Admin password reset error: {str(e)}')
+        return jsonify({
+            'status': 'error',
+            'message': 'An error occurred while resetting the password'
+        }), 500
+
 @bp.route('/debug-endpoints')
 def debug_endpoints():
     from flask import current_app