HS: fix log multi-arg parsing + put! position aliases + sender lookup

- parse-log-cmd now collects comma-separated args: log a, b, c
  previously only consumed the first arg, causing the rest to be
  standalone statement-commands that failed to parse
- compiler log case emits (do (console-log a) (console-log b) ...)
  since console-log is single-arg
- hs-put! accepts before/after/start/end as aliases for the
  beforebegin/afterend/afterbegin/beforeend positions
- hs-sender uses (get detail "sender") — direct SX dict lookup
  instead of host-get round-trip through JS

Fixes "can reference sender in events" test: 8/8 hs-upstream-send

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

lib/hyperscript/compiler.sx

@@ -2017,7 +2017,11 @@
                 ((= head (quote wait)) (list (quote hs-wait) (nth ast 1)))
                 ((= head (quote wait-for)) (emit-wait-for ast))
                 ((= head (quote log))
-                  (list (quote console-log) (hs-to-sx (nth ast 1))))
+                  (cons
+                    (quote do)
+                    (map
+                      (fn (arg) (list (quote console-log) (hs-to-sx arg)))
+                      (rest ast))))
                 ((= head (quote send)) (emit-send ast))
                 ((= head (quote trigger))
                   (let