core: spec 35-var batch A — 1.11 parsers, map/partition variants, with-redefs, ns fns

Fifteen vars from the spec coverage gap (docs/spec/coverage.md):
parse-long/parse-double/parse-boolean (strict validation; scan-number alone
accepts 0x10), newline, current-time-ms (host clock for time), update-keys/
update-vals (PHM base, collisions last-wins), partitionv/partitionv-all/
splitv-at (lazy seqs of vectors; splitv-at's tail stays a seq, matching the
reference), with-redefs/with-redefs-fn (roots restored on throw), time,
macroexpand (expand-1 to fixpoint), alias/ns-unalias (write BOTH alias stores
— require :as uses string-keyed :imports while ns-aliases reads :aliases;
split filed), ns-publics (symbol-keyed map; publics == interns, no privacy).

Three pre-existing bugs fixed along the way:
- (partition n step pad coll) misparsed pad as the coll and returned ()
- (require 'bare.symbol) rejected — only vector specs were accepted
- analyze-form leaked the interpreted analyzer's ns on a punt: a throw out of
  the analyzer left current-ns=jolt.analyzer and :compile-ns set, so the
  fallback interpretation resolved user vars against the wrong namespace
  (bit (var user-sym) under compile mode)

And one overlay-authoring landmine documented in-code: a 20-coll fn must not
use 30-macros macros (with-redefs-fn's dotimes compiled as a forward ref that
resolved to the macro fn at runtime) — loop/recur instead.

Gate: conformance 316x3 (+14 rows), suite 4324 pass / 78 clean (was 4081/72;
parse_*/update_* files now contribute), baselines raised, all specs+unit,
fixpoint, self-host, sci, staged. Coverage: missing-portable 35 -> 20.

jolt-core/clojure/core/20-coll.clj

@@ -287,6 +287,46 @@
 (defn tagged-literal? [x]     (= (get x :jolt/type) :jolt/tagged-literal))
 (defn record? [x]             (some? (get x :jolt/deftype)))
 (defn uuid? [x]               (= (get x :jolt/type) :jolt/uuid))
+
+;; Clojure 1.11 map transformers. PHM base so transformed keys canonicalize
+;; (collisions: last entry in seq order wins, matching the reference).
+(defn update-keys [m f]
+  (reduce-kv (fn [acc k v] (assoc acc (f k) v)) (hash-map) m))
+
+(defn update-vals [m f]
+  (reduce-kv (fn [acc k v] (assoc acc k (f v))) (hash-map) m))
+
+;; Vector-returning partition variants (1.11): lazy seqs OF vectors.
+(defn partitionv
+  ([n coll] (map vec (partition n coll)))
+  ([n step coll] (map vec (partition n step coll)))
+  ([n step pad coll] (map vec (partition n step pad coll))))
+
+(defn partitionv-all
+  ([n coll] (map vec (partition-all n coll)))
+  ([n step coll] (map vec (partition-all n step coll))))
+
+;; First part a vector, rest a seq — matching the reference implementation.
+(defn splitv-at [n coll]
+  [(vec (take n coll)) (drop n coll)])
+
+;; with-redefs-fn: temporarily set each var's root to the mapped value, run
+;; the thunk, restore the saved roots even on throw. The with-redefs macro
+;; (30-macros) builds the {var val} map from names.
+(defn with-redefs-fn [binding-map func]
+  (let [vars (vec (keys binding-map))
+        saved (mapv var-get vars)]
+    (doseq [v vars] (var-set v (get binding-map v)))
+    (try
+      (func)
+      (finally
+        ;; loop/recur, not dotimes: dotimes is a 30-macros macro and this tier
+        ;; compiles before it exists (a forward ref would resolve to the macro
+        ;; fn at runtime and mis-apply it).
+        (loop [i 0]
+          (when (< i (count vars))
+            (var-set (nth vars i) (nth saved i))
+            (recur (inc i))))))))
 ;; Jolt has no chunked seqs (Phase 5 territory), so this is always false.
 (defn chunked-seq? [x] false)