fix(streamReader): implement scheduled cleanup for expired stream readers

[Gezi-lzq]

fix #2716

[Copilot]

Pull Request Overview

This PR implements scheduled cleanup for expired stream readers to fix issue #2716. The solution adds automatic cleanup of expired StreamReader instances that could accumulate and cause memory leaks.

• Adds scheduled cleanup task that runs every minute to remove expired StreamReaders
• Implements manual cleanup trigger method for testing expired StreamReader removal
• Creates comprehensive test coverage for StreamReader lifecycle and cleanup functionality

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

File	Description
StreamReaders.java	Implements scheduled cleanup task and adds testing methods for monitoring active readers
StreamReadersTest.java	Adds comprehensive test suite covering reader creation, reuse, manual cleanup, and periodic cleanup

Comments suppressed due to low confidence (1)

s3stream/src/test/java/com/automq/stream/s3/cache/blockcache/StreamReadersTest.java:90

• The test uses production scheduling intervals which makes tests slow and unreliable. Consider adding a constructor parameter or test-specific configuration to control cleanup intervals for faster, more reliable tests.

        streamReaders = new StreamReaders(Long.MAX_VALUE, objectManager, objectStorage, objectReaderFactory, 2);