HS: collectionExpressions +4 (then on click, undefined where, component template)

- parser: nil return in parse-cmd for feature keywords (on/init/def/behavior/live)
  so "then on click" correctly hands off to outer coll-feats loop
- compiler: cek-try wrap for undefined variable refs in coll-where compilation
  so "doesNotExist where it > 1" returns nil instead of throwing
- integration: hs-activate! detects script[type=text/hyperscript-template] and
  applies handler to DOM instances via hs-query-all(component attr) not to script el

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

lib/hyperscript/compiler.sx

@@ -1107,13 +1107,21 @@
                     (hs-to-sx (nth ast 1))
                     (nth ast 2)))
                 ((= head (quote coll-where))
-                  (list
-                    (quote filter)
+                  (let
+                    ((raw-coll (hs-to-sx (nth ast 1))))
                     (list
-                      (quote fn)
-                      (list (quote it))
-                      (hs-to-sx (nth ast 2)))
-                    (hs-to-sx (nth ast 1))))
+                      (quote filter)
+                      (list
+                        (quote fn)
+                        (list (quote it))
+                        (hs-to-sx (nth ast 2)))
+                      (if
+                        (symbol? raw-coll)
+                        (list
+                          (quote cek-try)
+                          (list (quote fn) (list) raw-coll)
+                          (list (quote fn) (list (quote _e)) nil))
+                        raw-coll))))
                 ((= head (quote coll-sorted))
                   (list
                     (quote hs-sorted-by)

lib/hyperscript/integration.sx

@@ -115,7 +115,15 @@
             (dom-set-data el "hs-script" src)
             (dom-set-data el "hs-active" true)
             (dom-set-attr el "data-hyperscript-powered" "true")
-            (let ((handler (hs-handler src))) (handler el))
+            (let
+              ((handler (hs-handler src)))
+              (let
+                ((el-type (dom-get-attr el "type"))
+                  (comp-name (dom-get-attr el "component")))
+                (if
+                  (= el-type "text/hyperscript-template")
+                  (for-each handler (hs-query-all (or comp-name "")))
+                  (handler el))))
             (dom-dispatch el "hyperscript:after:init" nil)))))))
 
 ;; ── Boot subtree: for dynamic content ───────────────────────────

lib/hyperscript/parser.sx

@@ -2783,6 +2783,8 @@
                       ((body (parse-cmd-list)))
                       (match-kw "end")
                       (list (quote view-transition!) using body)))))
+              ((and (= typ "keyword") (or (= val "on") (= val "init") (= val "def") (= val "behavior") (= val "live")))
+                nil)
               (true (parse-expr))))))
       (define
         parse-cmd-list