The plugin_loaded event was emitted on every plugin reload, generating
high event volume on PostHog (proportional to opencode restarts per
user per day). With MAU > 60K and active power users restarting
frequently, this drove unnecessary event spend.
Add a separate daily dedup state field (lastPluginLoadedDayUTC) so the
plugin_loaded capture only fires once per UTC day per machine. The
existing daily activity dedup (lastActiveDayUTC, used by
omo_daily_active) is preserved as an independent gate so the two
dimensions cannot overwrite each other in the activity state file.