Stage 4 of docs/modules/rust/PLAN_LAST_FIXES.md, the module's half of W1.
A placed zone now reports `until`, reckoned from the answer as now plus
holdMs, so it lands a round trip after the game's own deadline and never
before it. Core's reconcile then files a zone gone past that deadline as
expired, where a reconnect used to log resource.orphaned five seconds
before the game's world.expired arrived. Crates and NPCs send no
holdMs, so they carry no until.
No core pin change: `until` has been in the resource contract all along,
and a core without the reconcile half only shows it on the console.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01E14m6SuuY6i1vASFeGDBeY
