Registry changes from dict[str,Capability] to dict[str,list[Capability]].
discover() gains pattern_caps parameter (fallback for unmatched hrefs)
and gates each candidate on rt_filter and match_fn before binding.
Duplicate hrefs in registry allowed only if all caps set a discriminator.
OCF rt is a schema category shared by many unrelated resources.
The stable unique resource address is the href. Update Capability,
discovery, common capabilities, tests, and plan accordingly.
Marc Billow