HS E37: tokenizer-as-API 17/17 (+fixes)

- runtime.sx: fix extra ) in hs-tokens-of (parse error); add hs-eof-sentinel,
  hs-raw->api-token, hs-normalize-raw-tokens, hs-tokens-of, stream helpers,
  hs-token-type/value/op?; add \$ escape to hs-template
- tokenizer.sx: fix read-number double-dot bug (1.1.1 → 3 tokens); fix t-emit!
  eof call (3→2 args); add bare $ case to scan-template!
- compiler.sx: add \$ escape to tpl-collect template interpolation
- generate-sx-tests.py: preserve \$ in process_hs_val; add generate_tokenizer_test
- regen spec/tests/test-hyperscript-behavioral.sx: 17 tokenizer tests generated
- plans/hs-conformance-to-100.md: row 37 marked done +17

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

lib/hyperscript/compiler.sx

@@ -893,6 +893,12 @@
                           (let
                             ((ch (nth raw i)))
                             (if
+                              (and (= ch "\\") (< (+ i 1) n) (= (nth raw (+ i 1)) "$"))
+                              (do
+                                (set! buf (str buf "$"))
+                                (set! i (+ i 2))
+                                (tpl-collect))
+                              (if
                               (and (= ch "$") (< (+ i 1) n))
                               (if
                                 (= (nth raw (+ i 1)) "{")
@@ -931,7 +937,7 @@
                               (do
                                 (set! buf (str buf ch))
                                 (set! i (+ i 1))
-                                (tpl-collect)))))))
+                                (tpl-collect))))))))
                     (tpl-collect)
                     (tpl-flush)
                     (cons (quote str) parts))))