edn: port read-string onto the reader; fix special-form ns shadowing

clojure.edn/read-string now delegates to clojure.core/read-string (the
reader-based special form — parses, never evals) via a private helper, with the
opts-map :eof arity and nil/blank-input handling. 43 -> 47 in the stdlib battery.

This required an evaluator fix: special forms were matched by name only, so
clojure.edn/read-string dispatched the core read-string SPECIAL FORM instead of
the var. Now a head qualified to a non-core namespace resolves to its var; only
unqualified or clojure.core-qualified heads are special forms. Conformance
218/218 all modes; full suite green.

Remaining edn gaps (jolt-b7y): set literals read as a set FORM not a constructed
set, and #uuid has no real type.

src/jolt/clojure/edn.clj

@@ -1,13 +1,27 @@
-; Jolt Standard Library: clojure.edn
-; EDN reading and writing (stubs using the Jolt reader).
+;; clojure.edn — reading EDN data. Delegates to the Jolt reader via
+;; clojure.core/read-string (which parses, never evaluates — safe for EDN), and
+;; adds the opts-map arity with :eof plus nil/blank-input handling.
+(ns clojure.edn
+  "Reading EDN data."
+  (:require [clojure.string :as cstr]))
+
+;; Private helper, NOT named read-string: an unqualified (read-string …) call
+;; dispatches the core read-string SPECIAL FORM (by name, regardless of ns), so
+;; the 1-arity can't delegate to the 2-arity through that name.
+(defn- read-edn [opts s]
+  (if (or (nil? s) (cstr/blank? s))
+    (get opts :eof nil)
+    (clojure.core/read-string s)))
 
 (defn read-string
-  [s]
-  (let [ctx ((get (dyn :current-env) (symbol "init")))]
-    ((get (dyn :current-env) (symbol "eval-string")) ctx s)))
+  "Reads one object from the string s. Returns the :eof option value (default
+  nil) for nil or blank input. opts is an options map; :eof sets the value
+  returned at end of input."
+  ([s] (read-edn {} s))
+  ([opts s] (read-edn opts s)))
 
 (defn read
+  "Reads the next line from reader and parses one EDN object from it."
   [reader]
   (let [line ((get (dyn :current-env) (symbol "file/read")) reader :line)]
-    (when line
-      (read-string line))))
+    (when line (read-string line))))

src/jolt/evaluator.janet

@@ -611,9 +611,13 @@
 (defn- eval-list
   [ctx bindings form]
   (def first-form (first form))
-  # Safe name extraction: non-symbol heads (e.g. keywords) fall through to default
+  # Safe name extraction: non-symbol heads (e.g. keywords) fall through to default.
+  # A head qualified to a NON-core namespace (e.g. clojure.edn/read-string) must
+  # resolve to that var, not the like-named clojure.core special form — so only
+  # unqualified or clojure.core-qualified heads dispatch as special forms.
   (def name (if (and (struct? first-form) (= :symbol (first-form :jolt/type)))
-              (first-form :name)
+              (let [ns (first-form :ns)]
+                (if (or (nil? ns) (= ns "clojure.core")) (first-form :name) nil))
               nil))
   (match name
     "quote" (in form 1)

test/integration/clojure-stdlib-suite-test.janet

@@ -12,9 +12,10 @@
   [["clojure/walk_test/walk.cljc"            34 true]
    ["clojure/zip_test/zip.cljc"              33 true]
    ["clojure/data_test/diff.cljc"            61 true]
-   # clojure.edn is still a stub (no opts/:eof arity, broken set/nil handling);
-   # tracked separately. Guard its current passing subset so it can't regress.
-   ["clojure/edn_test/read_string.cljc"      43 false]])
+   # clojure.edn now reads via clojure.core/read-string with opts/:eof + nil/blank
+   # handling. The remaining 3 fails are sets (the reader yields a set FORM, not a
+   # constructed set) and #uuid — tracked in jolt-b7y. Guard the passing subset.
+   ["clojure/edn_test/read_string.cljc"      47 false]])
 
 (def root "test/clojure-stdlib")
 (def per-file-timeout 6)