Follow-up to ScotterMonk's cron-truncation fix:
- Remove HERMES_DELIVERY_MAX_PLATFORM_OUTPUT env var. Behavioral config
belongs in config.yaml, not a new HERMES_* env var (.env is secrets
only). The actual bug is fixed entirely by the adapter-aware skip; the
configurable cap was unneeded scope. MAX_PLATFORM_OUTPUT is a constant
again, collapsing the max_output=0 disable branch and the
audit-vs-truncation threshold divergence.
- Flag the remaining verified-chunking adapters (slack, matrix, feishu,
mattermost, teams, whatsapp, whatsapp_cloud, weixin, bluebubbles,
yuanbao) with splits_long_messages=True so the fix covers the whole
bug class, not just Discord/Telegram. Each verified to chunk in its
own send() via truncate_message().
- SMS deliberately left False: it chunks for normal replies but a
multi-segment cron blast is cost-bearing; the 4000-cap + file save is
the safer default there.
- Update tests: drop the two env-override tests, add a test asserting a
save failure during truncation (non-chunking) propagates.
