[enhancement] Business Metric Monitoring​

Unlike service performance and availability metrics, ​​business metrics​​ are custom-defined indicators that can be preset in monitoring configurations. By integrating with ​​OzHera's alerting functionality​​, they enable ​​business-level monitoring and alerting​​.

**What constitutes a business-level metric?​​**

For example:

- In an e-commerce system, verifying whether the **​​order amount​​** matches the ​​**financial payment amount​​.**
- Tracking whether ​​**coupon issuance**​​ aligns with ​​**coupon redemption​​.**

These metrics help ​​**quickly identify discrepancies**​​ in business logic, allowing teams to **​​detect and mitigate issues early​​**, minimizing potential losses in critical scenarios.

This enhancement empowers businesses to **​​proactively monitor operational health**​​ and take corrective actions when anomalies arise.

The issue does not name files, tests, or entry points. Start by locating OzHera’s existing monitoring configuration and alerting functionality, then determine how custom business metrics and their alert conditions should be represented. Done should include an agreed scope for the example discrepancy checks and tests covering the resulting monitoring behavior.

Written by the indexing model from the issue text.