[Hardening] F-09: No Email Alerts for Security-Relevant Events.

### The required feature described as a wish

**Description:** CloudStack does not send email notifications to users or administrators when security-relevant events occur on their accounts. Specifically, no alerts are generated for password changes, creation of API keys, failed login attempts, or exposure of data containing secrets, such as `kubeconfig`.

**Affected Components:** Management

**Impact:** Since users have no out-of-band visibility into actions taken on their accounts, an attacker may go undetected indefinitely, establish persistence by creating API keys, try to guess users' passwords, attempt to access users' accounts from an unauthorized source (see F-12), or silently lock the user out by resetting their password. This significantly increases the window of exposure following a credential compromise.

**Steps to Reproduce:**
- Log in to the CloudStack Management UI as any user.
- Change your own password.
- Generate API keys.
- Reveal Kubernetes configuration.
- Attempt to log in with an incorrect password.
- Attempt to log in from an unauthorized source.
- Check for an email notification confirming that any of the above actions occurred.

**Recommended Remediation:** Implement email notifications for security-sensitive account events, including but not limited to the ones listed above. Each notification should include the timestamp, source IP address, and nature of the action performed. All triggering events should additionally be recorded as audit log entries to support forensic investigation and compliance reporting.

未指定源文件或测试。先从密码更改、API-key 创建、登录失败或未授权登录以及 Kubernetes 配置暴露的 Management UI 流程入手，然后追踪其 audit-log 处理和通知路径。完成的标准是每个列出的安全事件都记录所需的审计数据，并发送一封包含其时间戳、source IP 和操作的电子邮件。

由索引模型根据 Issue 内容生成。