Class/forName claimed every java.*/clojure.* name found (and any "x.y.Class"
matched the registered Class via a short-name fallback), so a library's
(class-found? "optional.Dep") feature-probe always said yes — tools.logging then
tried to build the java.util.logging / log4j backends jolt lacks and crashed.
Resolve forName by exact registry lookup + an honest prefix that excludes the
unbacked optional packages (java.util.logging, javax.management), so the probe
sees them absent and skips the backend.
class of a persistent collection / namespace now reports its JVM class name
(clojure.lang.PersistentHashSet, …Namespace, …) instead of jolt's internal :set/
:object tag, and isa? consults JVM class assignability — Object as every class's
root plus a modeled clojure.lang/java.util hierarchy — so (isa? (class x) C) and a
class-keyed multimethod dispatch like the JVM (e.g. (isa? Keyword Object) was
false). Adds the bare class tokens (Fn/Namespace/Set/…) these dispatch on.
(type x) is unchanged — it keeps jolt's documented internal-keyword form. Six
JVM-certified corpus rows. make test green, 0 new divergences.
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