Implement periodic cleanup of expired rate-limiter entries to prevent
unbounded memory growth during long runtimes.
Changes:
- Create rate_limiter_cleanup task that calls cleanup_expired() every 30 minutes
- Register the task in the startup DAG alongside other background jobs
- Update rate_limiter module documentation with operational notes about the
cleanup lifecycle and memory management strategy
The cleanup is conservative and only removes IPs with no recent attempts
(all timestamps outside the rate-limit window), so active IPs are preserved.
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Lukas
c2dd9f5f55