The Codex gpt-5.5 compaction-threshold autoraise notice re-fired on every
agent init. Because the gateway rebuilds the agent per inbound message, the
notice spammed long-running Discord/Telegram/etc. sessions, and the only
documented remedy (`compression.codex_gpt55_autoraise false`) disables the
useful autoraise behavior itself.
Gate both emission surfaces — the CLI startup print and the gateway
`_compression_warning` replay — on a persisted per-profile marker under
`$HERMES_HOME` (`.codex_gpt55_autoraise_notice`), keyed on the from→to
percentages the notice displays. The notice now shows at most once per
profile; the autoraise still fires and `codex_gpt55_autoraise: false` still
disables it; and a later change to the raised threshold re-notifies once.
Docs updated to match.
