feat(strictness): seq/shuffle/NaN?/nthrest/nthnext reject bad args

- seq throws on non-seqables (numbers/functions); collections/strings/nil ok
- shuffle requires a collection (throws on numbers/strings/nil)
- NaN? throws on non-numbers
- nthrest/nthnext require a numeric count (nil count throws), clamp negative
  counts to the whole coll, and treat a nil coll as nil
- update inherits assoc's vector bounds/keyword-key checks

nan_qmark clean; shuffle 9/1; nthrest 13/1; nthnext 12/0/1; update 59/2/2.
clojure-test-suite pass 3880->3889. spec: seq/strictness-round-3 (14). jpm test green.

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

@@ -18,7 +18,7 @@
 
 # Baseline: assertions Jolt currently passes across the suite. Raise as Jolt
 # improves so a regression (previously-passing assertion breaking) is caught.
-(def baseline-pass 3875)
+(def baseline-pass 3885)
 # A file is "clean" when it ran with zero failures AND zero errors.
 (def baseline-clean-files 45)
 # Per-file wall-clock budget (seconds). Normal files finish in well under 1s;