Adds LITELLM_SUPPRESS_SPEND_LOG_TRACEBACKS env var. When set to true and the
proxy log level is INFO or above, spend-tracking error paths emit a single
ERROR line without the full traceback. Stack traces are preserved at DEBUG
and the Sentry / proxy_logging_obj.failure_handler path is unchanged.
The new spend_log_error helper is wired through the spend write hot path:
- DBSpendUpdateWriter (update_database, _update_*_db, batch upsert,
redis-commit fallbacks)
- _ProxyDBLogger._PROXY_track_cost_callback
- get_logging_payload exception path
- update_spend / update_daily_tag_spend / spend logs queue monitor
Resolves LIT-2704.
Co-authored-by: Mateo Wang <mateo-berri@users.noreply.github.com>
