Three new pattern matching features in evaluator.sx:
1. Dict patterns in match:
(match {:name "Alice" :age 30}
({:name n :age a} (list n a))) ;; => ("Alice" 30)
2. &rest in list patterns:
(match (list 1 2 3 4 5)
((a b &rest tail) tail)) ;; => (3 4 5)
3. let-match form (sugar for match):
(let-match {:x x :y y} {:x 3 :y 4}
(+ (* x x) (* y y))) ;; => 25
Also: transpiler fix — "extra" key added to CekFrame cf_extra mapping
(was the root cause of thread-last mode not being stored).
2644 tests pass, zero regressions.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>