Chez Phase 1 (increment 3r): dynamic-var constants

host/chez/dynamic-vars.ss binds the two seed-native dynamic vars that aren't
emitted into the prelude: *clojure-version* (the {:major 1 :minor 11 ...} map) and
*unchecked-math* (false). Removes their two run-corpus-prelude allowlist entries
(now 11, all passing).

*ns* is deferred to jolt-b4kl: it needs a namespace value that is not a map yet
answers (get ns :name) for the overlay ns-name, plus str/find-ns support.

Parity 1530 -> 1532/2497, 0 new divergences. emit-test 305/305.

host/chez/dynamic-vars.ss

@@ -0,0 +1,16 @@
+;; dynamic vars (jolt-9ls5) — the handful of clojure.core dynamic vars the seed
+;; binds natively (src/jolt/core.janet) that aren't emitted into the prelude, so
+;; they var-deref to nil on Chez. These two are plain constants; *ns* (a namespace
+;; object) needs a value type with get-see-through and map?=false and is tracked
+;; separately. Loaded from rt.ss after the value model + def-var!.
+
+;; *clojure-version* — a jolt map {:major 1 :minor 11 :incremental 0 :qualifier nil}
+;; (jolt is all-flonum, so the numbers are flonums).
+(def-var! "clojure.core" "*clojure-version*"
+  (jolt-hash-map (keyword #f "major") 1.0
+                 (keyword #f "minor") 11.0
+                 (keyword #f "incremental") 0.0
+                 (keyword #f "qualifier") jolt-nil))
+
+;; *unchecked-math* — jolt does no unchecked-math elision; the var reads false.
+(def-var! "clojure.core" "*unchecked-math*" #f)

host/chez/rt.ss

@@ -170,3 +170,7 @@
 ;; (seq.ss), jolt=/key-hash/jolt-hash-map (collections.ss), jolt-atom? (atoms.ss),
 ;; jolt-pr-str (above), and the var-cell machinery — so loaded last.
 (load "host/chez/multimethods.ss")
+
+;; dynamic vars (jolt-9ls5): *clojure-version* / *unchecked-math* constants the seed
+;; binds natively. After collections.ss (jolt-hash-map) + def-var!.
+(load "host/chez/dynamic-vars.ss")