Investigate and fix memory leak in Manager

A memory leak has been observed in the Manager component. Memory usage grows steadily over time and is not reclaimed.

Goal:

- Reproduce and measure the memory growth in Manager.
- Identify the root cause (retained references, unbounded caches/queues, unclosed resources, etc.).
- Apply a fix and verify that memory usage stabilizes under sustained load.

JIRA Issue: BA-6792

No files, tests, or entry points are named. Start by reproducing and measuring memory growth in the Manager component under sustained load, then trace retained references, unbounded caches or queues, and unclosed resources; done means memory usage stabilizes after the fix.

Written by the indexing model from the issue text.