Greptile Summary

Added periodic media cleanup timer that runs hourly to remove old files from ~/.openclaw/media/ based on a configurable TTL (default: 24 hours via media.ttlHours).

Key changes:

• cleanOldMedia() in src/media/store.ts walks the media directory and first-level subdirectories, removing files older than the configured TTL based on modification time
• Gateway maintenance timers schedule cleanup to run hourly plus once on startup
• Configuration properly validated via Zod schema (non-negative numbers only)
• Cleanup interval properly cleared during gateway shutdown
• Comprehensive test coverage for both the cleanup logic and timer scheduling

Implementation notes:

• The cleanup uses mtime for age calculation, which is appropriate for this use case
• Error handling uses silent catches for individual file operations while logging errors at the top level
• The Math.max(0, mediaTtlHours) provides defense-in-depth even though Zod already validates non-negative values
• Cleanup runs every hour (60 * 60_000 ms), which is reasonable for the default 24-hour retention window

Confidence Score: 5/5

• This PR is safe to merge with no identified issues
• The implementation is clean and well-tested. Configuration validation is thorough with Zod schema, edge cases are handled correctly (Infinity, NaN, negative values), cleanup logic is sound and matches current usage patterns, timer lifecycle management is complete with proper shutdown cleanup, and test coverage is comprehensive covering both unit tests for cleanup logic and integration tests for timer scheduling.
• No files require special attention

_{Last reviewed commit: c63cc62}

Picked this up in #38292 so the final media fix can land as one scoped PR.

That branch carries forward the top-level media.ttlHours config and gateway-owned cleanup timer from this PR, then folds in the nested-directory coverage from #29211 so issue #33078 is handled end to end.

Keeping this linked for contributor credit because the retention-config and gateway-lifecycle pieces came from here.

Resolved in #38292