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.

test/spec/sequences-spec.janet

@@ -261,3 +261,15 @@
   ["dedupe consecutive"        "[1 2 3 1]" "(dedupe [1 1 2 2 3 1 1])"]
   ["dedupe empty"              "[]"     "(dedupe [])"]
   ["dedupe no dups"            "[1 2 3]" "(dedupe [1 2 3])"])
+
+# Clojure 1.11 vector-returning partition/split variants.
+(defspec "seq / partitionv & splitv-at (1.11)"
+  ["partitionv"         "[[1 2] [3 4]]"  "(partitionv 2 [1 2 3 4 5])"]
+  ["partitionv elems are vectors" "true" "(every? vector? (partitionv 2 [1 2 3 4]))"]
+  ["partitionv step"    "[[1 2] [3 4]]"  "(partitionv 2 2 [1 2 3 4 5])"]
+  ["partitionv pad"     "[[1 2] [3 :p]]" "(partitionv 2 2 [:p] [1 2 3])"]
+  ["partitionv-all"     "[[1 2] [3]]"    "(partitionv-all 2 [1 2 3])"]
+  ["partitionv-all vectors" "true"       "(every? vector? (partitionv-all 2 [1 2 3]))"]
+  ["splitv-at"          "[[1 2] [3 4]]"  "(splitv-at 2 [1 2 3 4])"]
+  ["splitv-at first is vector" "true"    "(vector? (first (splitv-at 2 [1 2 3])))"]
+  ["splitv-at past end" "[[1 2] []]"     "(splitv-at 5 [1 2])"])