nx_lifecycle.nx

nx_lifecycle.nx -- LIB: the WEAR / REPAIR / ETERNAL lifecycle twin. Adds the time dimension to the product twin: per part a wear life (days), a part cost and a LABOR (effort) cost to replace, and whether it is replaceable. From these the system is judged in three regimes (operator's framing): ETERNAL -- every part replaceable -> the system lasts forever, swapped piece by piece (Ship of Theseus). EVOLVING -- each replacement uses a BETTER part -> capability ratchets up over cycles. LIMITED -- when the LABOR to replace exceeds the part cost, early refresh wastes effort, so replacement is RECOMMENDED only after X days (at wear-out); a non-replaceable part caps the whole system's life. never-brick #26: pure arithmetic, bounded, deterministic. license_tier: ORIGINAL