Add timestamps to quarz discs

Black boxes are dated, quarz discs are not. That makes it extremely hard to anchor the events they describe in the timeline.

Example: In the latest (0.1.2) update, a quarz disc of Sophie declaring an exclusion zone around Karakorum was added. When was that supposed to have been recorded? We know from the black boxes that only a little more than a month before Nahema’s terrorist attack, everybody including the cook was happily puttering around (and dying) in Karakorum

Suggestion: add timestamps to quarz discs to better tie them into the timeline of events.