HS: open/close commands for dialog/details — 428→435

- Parser: open/close commands with optional target (defaults to me)
- Compiler: open-element → hs-open!, close-element → hs-close!
- Runtime: hs-open! calls showModal() for dialogs, sets open=true for details
- Runtime: hs-close! calls close() for dialogs, sets open=false for details
- dialog: 1/10 → 8/10

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

lib/hyperscript/parser.sx

@@ -1495,6 +1495,20 @@
             ((lhs (parse-expr)))
             (match-kw "with")
             (let ((rhs (parse-expr))) (list (quote swap!) lhs rhs)))))
+      (define
+        parse-open-cmd
+        (fn
+          ()
+          (let
+            ((target (cond ((at-end?) (list (quote me))) ((and (= (tp-type) "keyword") (or (= (tp-val) "then") (= (tp-val) "end"))) (list (quote me))) (true (parse-expr)))))
+            (list (quote open-element) target))))
+      (define
+        parse-close-cmd
+        (fn
+          ()
+          (let
+            ((target (cond ((at-end?) (list (quote me))) ((and (= (tp-type) "keyword") (or (= (tp-val) "then") (= (tp-val) "end"))) (list (quote me))) (true (parse-expr)))))
+            (list (quote close-element) target))))
       (define
         parse-cmd
         (fn
@@ -1582,6 +1596,10 @@
                 (do (adv!) (parse-empty-cmd)))
               ((and (= typ "keyword") (= val "swap"))
                 (do (adv!) (parse-swap-cmd)))
+              ((and (= typ "keyword") (= val "open"))
+                (do (adv!) (parse-open-cmd)))
+              ((and (= typ "keyword") (= val "close"))
+                (do (adv!) (parse-close-cmd)))
               (true (parse-expr))))))
       (define
         parse-cmd-list
@@ -1630,7 +1648,9 @@
                 (= v "focus")
                 (= v "empty")
                 (= v "clear")
-                (= v "swap"))))
+                (= v "swap")
+                (= v "open")
+                (= v "close"))))
           (define
             cl-collect
             (fn