feat: run the real clojure.tools.logging (defmacro/syntax-quote/ns + host shims)

Pivot from a jolt reimplementation to running the upstream library verbatim.
Vendors the real clojure/tools/logging.clj; jolt provides the backend and the
host primitives it needs. Language features (broadly useful for real Clojure
libs), all covered in 3-mode conformance + spec suites:

- defmacro: multi-arity dispatch (jolt-q8l) and a docstring + attr-map + params
  head (jolt-qnr) — the 4-arity log macro and every level macro need these.
- syntax-quote resolves an alias-qualified symbol to its target ns (jolt-9av),
  so a macro template (impl/get-logger) resolves at the use site.
- the ns macro unwraps ^{:map} metadata on the ns name (jolt-8w2 workaround,
  matching def/defn/defmacro).
- a namespace object self-evaluates, so ~*ns* can be spliced into a template.

Host shims (ported from / modeled on clojure where applicable):
- clojure.string/trim-newline (ported, CharSequence interop -> count/subs)
- agent/send-off/send (minimal synchronous stubs; jolt has no thread pool/STM)
- clojure.lang.LockingTransaction/isRunning -> false
- a minimal clojure.pprint (pprint/with-pprint-dispatch/code-dispatch, for spy)
- clojure.tools.logging.impl: a jolt stderr LoggerFactory backend (the library's
  designed pluggable extension point)

docs/libraries.md lists tools.logging; grammar.ebnf metadata note clarified.
Conformance 355/355 x3 modes; full jpm test gate green.

test/spec/macros-spec.janet

@@ -93,3 +93,16 @@
   ["docstring + arity"    "15"  "(do (defmacro th \"triple\" ([x] (list (quote *) x 3))) (th 5))"]
   ["^{:map} name meta"    "7"   "(do (defmacro ^{:private true} pm [] 7) (pm))"]
   ["multi-form body"      "6"   "(do (defmacro mb ([a b] (list (quote +) a b))) (mb 2 4))"])
+
+# Multi-arity defmacro (dispatch on arg count) and the docstring + attr-map +
+# params form — both needed to run real Clojure macros, e.g.
+# clojure.tools.logging/log (4 arities) and its level macros (jolt-q8l, jolt-qnr).
+(defspec "macros / defmacro multi-arity & attr-map"
+  ["multi-arity 1"   "6"  "(do (defmacro ma ([a] (list (quote +) a 1)) ([a b] (list (quote +) a b))) (ma 5))"]
+  ["multi-arity 2"   "5"  "(do (defmacro ma ([a] (list (quote +) a 1)) ([a b] (list (quote +) a b))) (ma 2 3))"]
+  ["arity delegates" "[:d nil 9]"
+   "(do (defmacro lg ([m] `(lg :d nil ~m)) ([l t m] (list (quote vector) l t m))) (lg 9))"]
+  ["doc + attr-map + params" "10"
+   "(do (defmacro am \"doc\" {:arglists (quote ([x]))} [x] (list (quote inc) x)) (am 9))"]
+  ["doc + attr-map + variadic" "6"
+   "(do (defmacro vg \"d\" {:arglists (quote ([& a]))} [& xs] `(+ ~@xs)) (vg 1 2 3))"])