📅 The shape of a universe: eras that always matter

Forty eras, and some of them always carry a moment. Era 5: first contact — your nearest neighbour sends terms (a pact, a payment, or nothing), and your answer is remembered. Era 10: the last stable era — the Council sets a hardening list (a Gluon Shield, the energy store at 80%, an Electrolyser, a Fusion Reactor under way); done before the star turns, every government takes note. Eras 13–18: a neighbouring blue giant dies within reach — two eras of warning, then its blast front hits the dome and the rigs. Era 22: the Rift Theory names a site; the first to survey it holds the ground (Accord credits count 8% more). Era 34: the Long Night, announced at era 30 — one era when the star gives a fifth and flares come twice as often. Era 39: the last raids, when the pirates and warlords take what can still be carried.