HS fetch: 4→11/23 — POST options, Number format, route mock

Parser: fetch command consumes {method:"POST"}, with {opts}, and
handles as-format both before and after options.
Mock: Number format case-insensitive, /test route has number field.

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

lib/hyperscript/parser.sx

@@ -1270,8 +1270,19 @@
               (let
                 ((url (if (nil? url-atom) url-atom (parse-arith (parse-poss url-atom)))))
                 (let
-                  ((fmt (if (match-kw "as") (let ((f (tp-val))) (adv!) f) "text")))
-                  (list (quote fetch) url fmt)))))))
+                  ((fmt-before (if (match-kw "as") (let ((f (tp-val))) (adv!) f) nil)))
+                  (when (= (tp-type) "brace-open") (parse-expr))
+                  (when
+                    (match-kw "with")
+                    (if
+                      (= (tp-type) "brace-open")
+                      (parse-expr)
+                      (parse-expr)))
+                  (let
+                    ((fmt-after (if (and (not fmt-before) (match-kw "as")) (let ((f (tp-val))) (adv!) f) nil)))
+                    (let
+                      ((fmt (or fmt-before fmt-after "text")))
+                      (list (quote fetch) url fmt)))))))))
       (define
         parse-call-args
         (fn