Auto-resolve ::keywords; honor clojure.edn reader opts

The reader dropped the namespace on ::kw (read ::foo as :foo), so auto-resolved
keywords never matched their qualified form — code that round-trips them (spec
keys, aero's :aero.core/* expansion keys) silently broke. Resolve ::name against
the current ns and ::alias/name through the alias table, as Clojure does. The
runtime loader reads form-by-form with the ns set after the ns form; the
cross-compile reads all forms up front, so ei-emit-ns*/ei-emit-ns-records set the
ns before reading.

clojure.edn/read over a reader discarded its opts map — :readers/:default/:eof
were ignored, so a custom :default never saw the tag. Route the reader arity
through read-string so opts apply, and pass the tag to :default as a symbol (not
the internal :#name keyword), matching Clojure.

Seed re-minted (the ::halt transducer key in clojure.core now reads as
:clojure.core/halt). Corpus gains ::-keyword rows; the unit case that asserted the
old ns-dropping behavior now asserts the qualified result.

stdlib/clojure/edn.clj

@@ -27,7 +27,8 @@
             custom (get (get opts :readers) tag-sym)]
         (cond
           custom (custom v)
-          (get opts :default) ((get opts :default) tag v)
+          ;; Clojure calls :default with the tag as a SYMBOL and the value.
+          (get opts :default) ((get opts :default) tag-sym v)
           :else (__read-tagged tag v)))
     (map? x)
       (into {} (map (fn [e] [(edn->value opts (key e)) (edn->value opts (val e))]) x))