fix(message-handler): cleanup stale pendingReplies to prevent memory leak

[kumudasrip]

Description of Changes

• Added lastActivity tracking for each pending reply entry in src/services/messageHandler.service.ts
• Implemented periodic cleanup of stale pendingReplies entries after the configured inactivity TTL
• Added configurable environment variables:
  • CHAT_BUDDY_PENDING_REPLY_TTL_HOURS
  • CHAT_BUDDY_PENDING_REPLY_CLEANUP_INTERVAL_MS
• Ensured cleanup timer is stopped gracefully on shutdown in src/cli/run.ts
• Documented the new cleanup settings in README.md

Related Issue Number

• Closes [BUG] Memory leak - pendingReplies Map never cleaned up, grows indefinitely #45

Type of Change

• Bug fix (non-breaking change which fixes an issue)

How Was This Tested

• Verified the code changes were applied in src/services/messageHandler.service.ts and src/cli/run.ts
• Confirmed no editor diagnostics/errors remain in the modified files
• Added targeted service tests for stale pending reply cleanup and buffered reply processing behavior

Checklist

• The code builds without errors (npm run build)
• Existing tests pass (npm test)
• New tests have been added if needed
• Documentation has been updated to reflect these changes if needed

[kumudasrip]

Hello @snackoverflowasad @shouri123
I have opened this new PR for the issue #45 , please do review it whenever possible so that I can get to know if the ci build tests are failing again or not, thank you!

[kumudasrip]

I pushed a small follow-up fix after the CI failure.

• I corrected the remaining local validation issue and reran the focused test.
• Local verification now passes:
• npm run build
• npm test -- --run src/services/messageHandler.service.test.ts --pool=forks

The CI failure looks related to the repo’s formatting/build checks rather than the new pendingReplies cleanup logic itself.

[kumudasrip]

I fixed the follow-up CI failure by removing the duplicate service test file and consolidating the new cleanup tests into the existing tests/messageHandlerService.test.ts suite.
npm test now passes cleanly with 130 tests.