HS: ask/answer + prompt/confirm mock (+4 tests)

Wire up the `ask` and `answer` commands end-to-end:

- tokenizer.sx: register `ask` and `answer` as hs-keywords.

- parser.sx: cmd-kw? gains both; parse-cmd dispatches to new
  parse-ask-cmd (emits `(ask MSG)`) and parse-answer-cmd, which
  reads `answer MSG [with YES or NO]`. The with/or pair reads
  yes/no via parse-atom — parse-expr would collapse
  `"Yes" or "No"` into `(or "Yes" "No")` before match-kw "or"
  could fire. The no-`with` form emits `(answer-alert MSG)`.

- compiler.sx: three new cond branches (ask, answer, answer-alert)
  compile to a let that binds __hs-a, sets `the-result` and `it`,
  and returns the value — so `then put it into ...` works.

- runtime.sx: hs-ask / hs-answer / hs-answer-alert call
  window.prompt / confirm / alert via host-call + host-global.

- tests/hs-run-filtered.js: test-name-keyed globalThis.{alert,
  confirm,prompt}; __currentHsTestName is updated before each
  test. Host-set! for innerHTML/textContent now coerces JS
  null → "null" (browser behaviour) so `prompt → null` →
  `put it into #out` renders literal text "null", which the
  fourth test depends on.

Suite hs-upstream-askAnswer: 1/5 -> 5/5.
Smoke 0-195: 166/195 -> 170/195.

lib/hyperscript/runtime.sx

@@ -468,6 +468,35 @@
 ;; `window.getSelection().toString()`.  In the mock test runner, a test
 ;; setup stashes the desired selection text at `window.__test_selection`
 ;; and the fallback path returns that so tests can assert on the result.
+(define
+  hs-ask
+  (fn
+    (msg)
+    (let
+      ((w (host-global "window")))
+      (if w (host-call w "prompt" msg) nil))))
+
+
+;; ── Transition ──────────────────────────────────────────────────
+
+;; Transition a CSS property to a value, optionally with duration.
+;; (hs-transition target prop value duration)
+(define
+  hs-answer
+  (fn
+    (msg yes-val no-val)
+    (let
+      ((w (host-global "window")))
+      (if w (if (host-call w "confirm" msg) yes-val no-val) no-val))))
+
+(define
+  hs-answer-alert
+  (fn
+    (msg)
+    (let
+      ((w (host-global "window")))
+      (if w (begin (host-call w "alert" msg) nil) nil))))
+
 (define
   hs-scroll!
   (fn
@@ -480,11 +509,6 @@
           ((= position "bottom") (dict :block "end"))
           (true (dict :block "start")))))))
 
-
-;; ── Transition ──────────────────────────────────────────────────
-
-;; Transition a CSS property to a value, optionally with duration.
-;; (hs-transition target prop value duration)
 (define
   hs-halt!
   (fn
@@ -619,6 +643,10 @@
       (hs-query-all sel)
       (host-call target "querySelectorAll" sel))))
 
+
+
+
+
 (define
   hs-list-set
   (fn
@@ -628,15 +656,12 @@
 (define
   hs-to-number
   (fn (v) (if (number? v) v (or (parse-number (str v)) 0))))
-
+;; ── Sandbox/test runtime additions ──────────────────────────────
+;; Property access — dot notation and .length
 (define
   hs-query-first
   (fn (sel) (host-call (host-global "document") "querySelector" sel)))
-
-
-
-
-
+;; DOM query stub — sandbox returns empty list
 (define
   hs-query-last
   (fn
@@ -644,10 +669,11 @@
     (let
       ((all (dom-query-all (dom-body) sel)))
       (if (> (len all) 0) (nth all (- (len all) 1)) nil))))
-
+;; Method dispatch — obj.method(args)
 (define hs-first (fn (scope sel) (dom-query-all scope sel)))
-;; ── Sandbox/test runtime additions ──────────────────────────────
-;; Property access — dot notation and .length
+
+;; ── 0.9.90 features ─────────────────────────────────────────────
+;; beep! — debug logging, returns value unchanged
 (define
   hs-last
   (fn
@@ -655,7 +681,7 @@
     (let
       ((all (dom-query-all scope sel)))
       (if (> (len all) 0) (nth all (- (len all) 1)) nil))))
-;; DOM query stub — sandbox returns empty list
+;; Property-based is — check obj.key truthiness
 (define
   hs-repeat-times
   (fn
@@ -673,7 +699,7 @@
               ((= signal "hs-continue") (do-repeat (+ i 1)))
               (true (do-repeat (+ i 1))))))))
     (do-repeat 0)))
-;; Method dispatch — obj.method(args)
+;; Array slicing (inclusive both ends)
 (define
   hs-repeat-forever
   (fn
@@ -689,9 +715,7 @@
             ((= signal "hs-continue") (do-forever))
             (true (do-forever))))))
     (do-forever)))
-
-;; ── 0.9.90 features ─────────────────────────────────────────────
-;; beep! — debug logging, returns value unchanged
+;; Collection: sorted by
 (define
   hs-repeat-while
   (fn
@@ -704,7 +728,7 @@
           ((= signal "hs-break") nil)
           ((= signal "hs-continue") (hs-repeat-while cond-fn thunk))
           (true (hs-repeat-while cond-fn thunk)))))))
-;; Property-based is — check obj.key truthiness
+;; Collection: sorted by descending
 (define
   hs-repeat-until
   (fn
@@ -716,7 +740,7 @@
         ((= signal "hs-continue")
           (if (cond-fn) nil (hs-repeat-until cond-fn thunk)))
         (true (if (cond-fn) nil (hs-repeat-until cond-fn thunk)))))))
-;; Array slicing (inclusive both ends)
+;; Collection: split by
 (define
   hs-for-each
   (fn
@@ -736,7 +760,7 @@
                 ((= signal "hs-continue") (do-loop (rest remaining)))
                 (true (do-loop (rest remaining))))))))
       (do-loop items))))
-;; Collection: sorted by
+;; Collection: joined by
 (begin
   (define
     hs-append
@@ -764,7 +788,7 @@
         ((hs-element? target)
           (dom-insert-adjacent-html target "beforeend" (str value)))
         (true nil)))))
-;; Collection: sorted by descending
+
 (define
   hs-sender
   (fn
@@ -772,7 +796,7 @@
     (let
       ((detail (host-get event "detail")))
       (if detail (host-get detail "sender") nil))))
-;; Collection: split by
+
 (define
   hs-host-to-sx
   (fn
@@ -826,7 +850,7 @@
                           (dict-set! out k (hs-host-to-sx (host-get v k))))
                         (host-call (host-global "Object") "keys" v))
                       out)))))))))))
-;; Collection: joined by
+
 (define
   hs-fetch
   (fn