PHP defaults to UTC on Unraid while every bash script stamps local time, and the
two write into the same files — conf_changes.log was four hours out from every
log you would correlate it against. The parsing half was worse: vv_ai_syslog_ts()
reads local-time syslog lines through strtotime() under UTC, landing every event
four hours early, and the repair sweep bounds its scan to "since the last pass"
— so a fault that had just happened could read as four hours old and fall
outside the window. Also fixes date-string comparisons against bandwidth and
cleanup dbs, which bash writes with local dates.