test: fold ported-clojure batteries into spec

Mine the remaining integration 'ported Clojure' batteries into the spec layer
and delete them (clojure-atom/control/for/logic/macros, core, logic). A broad
function-coverage diff confirmed they exercised no clojure.core fn the spec
lacked; their distinctive value was the truthiness/boolean contract, now
captured in a dedicated spec.

New/expanded spec coverage:
- spec/truthiness-spec: only nil/false are falsy (0, "", [], {}, #{} are truthy);
  not / and / or return-value & short-circuit semantics; if-not/when-not/boolean
- assert (exceptions-spec), get-validator (state-spec)

Layout now: spec 23 files / 732 cases; integration trimmed to 10 genuine
cross-cutting batteries (conformance, SCI bootstrap/runtime, jank, compile-mode,
api, namespace, bootstrap, features, systematic-coverage). conformance 218/218,
jpm test green.

README.md

@@ -99,7 +99,7 @@ Tests are organized in three layers:
   is the authoritative description of what Jolt promises.
 - **`test/integration/`** — cross-cutting and regression batteries: the Clojure
   conformance suite, SCI bootstrap/runtime loading, jank conformance, compile-mode
-  tests, and ported Clojure test batteries.
+  tests, the library API, and a broad systematic-coverage net.
 - **`test/unit/`** — white-box tests for individual components (reader,
   evaluator, types, persistent collections, regex, compiler).