Fix some primitive: return callback result, not element

List.find returns the element that matched, but SX some should return
the callback's truthy return value. This caused get-verb-info to return
"get" (the verb string) instead of the {method, url} dict.

Also added _active_vm tracking to VM for future HO primitive optimization,
and reverted get-verb-info to use some (no longer needs for-each workaround).

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

web/engine.sx

@@ -86,20 +86,13 @@
   :effects (io)
   (fn
     (el)
-    (let
-      ((result nil))
-      (for-each
-        (fn
-          (verb)
-          (when
-            (not result)
-            (let
-              ((url (dom-get-attr el (str "sx-" verb))))
-              (when
-                url
-                (set! result (dict "method" (upper verb) "url" url))))))
-        ENGINE_VERBS)
-      result)))
+    (some
+      (fn
+        (verb)
+        (let
+          ((url (dom-get-attr el (str "sx-" verb))))
+          (if url (dict "method" (upper verb) "url" url) nil)))
+      ENGINE_VERBS)))
 
 (define
   build-request-headers