HS E37 step 5: hs-tokenize-template + template routing in hs-tokens-of

Add hs-tokenize-template: scans " as single STRING token, ${ ... }
as dollar+brace+inner-tokens (inner tokenized with hs-tokenize), and
} as brace-close. Update hs-tokens-of to call hs-tokenize-template
when :template keyword arg is passed. Unlocks tests 1 and 15.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

lib/hyperscript/runtime.sx

@@ -2611,7 +2611,8 @@
   (fn
     (src &rest rest)
     (let
-      ((raw (hs-tokenize src)))
+      ((template? (and (> (len rest) 0) (= (first rest) :template)))
+       (raw (if template? (hs-tokenize-template src) (hs-tokenize src))))
       {:source src
        :list   (map hs-raw->api-token raw)
        :pos    0})))