fix(entrypoint): /home/lftp/.lftp-logs grows unbounded across runs

gh issue create --title "fix(entrypoint): /home/lftp/.lftp-logs grows unbounded across runs" --label "bug,audit,priority:medium" --body "## Finding

lftp writes debug logs to \$HOME/.lftp-logs (when debug is enabled). The action runs in a fresh container per job, so within a single run the logs are bounded; but on a self-hosted runner with a persistent HOME, the directory accumulates across runs. No rotation, no cleanup.

## Affected code

- entrypoint.sh — lftp invocation does not rotate or clean \$HOME/.lftp-logs

## Reproduction

1. Run the action many times on a self-hosted runner with persistent HOME.
2. Inspect /home/lftp/.lftp-logs: file count grows unbounded.

## Suggested fix

Either:
- Add a rotate step at the start of entrypoint.sh that keeps the last N log files (e.g. find \$HOME/.lftp-logs -type f -mtime +7 -delete).
- Or document that \$HOME should be ephemeral on self-hosted runners.
- Or set lftp's debug-level to a value that does not write to disk by default.

The first option is the cleanest.

## Source

F2 audit 2026-09-03 (entrypoint.sh audit). Reporter: subagent-pekodbj7.

## Related

- Part of EPIC #[epic-number]
- Closes: #NONE (no existing issue)"

Start with entrypoint.sh and inspect how the lftp invocation interacts with $HOME/.lftp-logs on a persistent HOME. Reproduce the issue by running the action repeatedly on a self-hosted runner and checking whether the file count grows. Done means the selected cleanup or rotation behavior keeps retained logs bounded across runs.

Do mô hình lập chỉ mục viết ra từ nội dung của issue.