Optional ReadonlycapabilityPhantom carrier for T. Never assigned, never read; declaring it is the
only way an interface can be generic in a value it does not hold.
ReadonlynameThe capability's identity, e.g. "fourJS:renderer-registry".
ReadonlyrevocableWhether a plugin that acquired this capability can still be uninstalled
(RFC 0002 §4). Default false, by owner decision (Q3, register row 6:
"conservative default (non-revocable)").
A typed key naming one thing a host can hand a plugin (RFC 0002 §2).
The type parameter is carried by PluginCapability.capabilityType, which is never present at runtime — it exists so that
context.require(RENDERER_REGISTRY)is aRendererRegistryto the compiler while this file names nothing but a string and a phantom type. That is what lets each registry's owning package declare its own token withoutcoregaining an edge to it, and what makes a sixth capability additive.