Provide a mechanism to purge the events table

### Is your feature request related to a problem? Please describe.

The `events` table is currently configured for indefinite growth, lacking a purge mechanism. Neither the Polaris server, nor any tool provided by the Apache Polaris project, offers a solution for purging this table.

To improve the experience for open-source users, a more robust strategy for managing the `events` table is needed.

### Describe the solution you'd like

_No response_

### Describe alternatives you've considered

_No response_

### Additional context

_No response_

The report identifies only the events table and the Polaris server or project tools; no file, entry point, or test is named. First locate the table definition and the code that records or reads events, then clarify the purge policy and operational interface. Done means users have a documented, testable way to remove eligible events.

Written by the indexing model from the issue text.