Row label for the freshness timestamp, mode-aware to match the
timestamp's actual meaning: only the source-validation modes truly validate the
cache against the server on each check ("Last Validated"). Under
ttl/none the timestamp is a fixed baseline marking when the cache was
established, not a per-check event, so "Cached Since" is the honest label.
Row label for the freshness timestamp, mode-aware to match the timestamp's actual meaning: only the source-validation modes truly validate the cache against the server on each check ("Last Validated"). Under ttl/none the timestamp is a fixed baseline marking when the cache was established, not a per-check event, so "Cached Since" is the honest label.