Fork L (docs/headless-playground-cut.md): pickup, impact absorption, melee
blade and propulsion are separate item capabilities that a future simulation
will own; presentations subscribe and decide nothing. This stands up the wire
shape only -- AbsorbEvent/GrabEvent/MeleeEvent/ThrustEvent plus a per-entity
CapabilityEvents source (UniRx Subject<T> per kind, matching the idiom
already used on Entity) -- with no publisher wired up yet. Compiles into the
headless Aetheria.Shared build with no Unity dependency.
AbsorbEvent carries the hit's DamageType (operator, 2026-09-17) so a future
presenter can vary visuals per type; the damage-type mask itself belongs to
the absorb capability's own data and is out of scope here.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
