HS: transition query-ref + multi-prop (+2 tests)

Three parts: (a) parser `collect-transitions` recognises `style`
tokens (`*prop`) as a continuation, so
`transition *width from A to B *height from A to B` chains both
transitions instead of dropping the second. (b) Mock `El` class gets
`nextSibling`/`previousSibling` (plus `*ElementSibling` aliases) so
`transition *W of the next <span/>` can resolve the next-sibling
target via host-get. (c) Generator pattern for
`const X = await evaluate(() => { const el = document.querySelector(SEL);
el.dispatchEvent(new Event(NAME, ...)); return ... })`; optionally
prefixed by a destructuring assignment and allowing trailing
`expect(...).toBe(...)` junk because `_body_statements` only splits on
`;` at depth 0.

Remaining `can use initial to transition to original value` needs
`on click N` count-filtered events (same mock-sync block as cluster 13).

Suite hs-upstream-transition: 13/17 → 15/17. Smoke 0-195: 162/195
unchanged.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

lib/hyperscript/parser.sx

@@ -1618,8 +1618,11 @@
                   (if
                     (and
                       (not (at-end?))
-                      (= (tp-type) "ident")
+                      (or
-                      (not (hs-keyword? (tp-val))))
+                        (= (tp-type) "style")
+                        (and
+                          (= (tp-type) "ident")
+                          (not (hs-keyword? (tp-val))))))
                     (collect-transitions
                       (append acc (list (parse-one-transition))))
                     acc)))

shared/static/wasm/sx/hs-parser.sx

@@ -1618,8 +1618,11 @@
                   (if
                     (and
                       (not (at-end?))
-                      (= (tp-type) "ident")
+                      (or
-                      (not (hs-keyword? (tp-val))))
+                        (= (tp-type) "style")
+                        (and
+                          (= (tp-type) "ident")
+                          (not (hs-keyword? (tp-val))))))
                     (collect-transitions
                       (append acc (list (parse-one-transition))))
                     acc)))

spec/tests/test-hyperscript-behavioral.sx

@@ -12798,6 +12798,7 @@ end")
       (dom-set-attr _el-div "_" "on click transition *width from 0px to 100px *height from 0px to 100px")
       (dom-append (dom-body) _el-div)
       (hs-activate! _el-div)
+      (dom-dispatch _el-div "click" nil)
       (assert= (dom-get-style _el-div "width") "100px")
       (assert= (dom-get-style _el-div "height") "100px")
     ))

tests/hs-run-filtered.js

@@ -52,6 +52,10 @@ class El {
   contains(o) { if(o===this)return true; for(const c of this.children)if(c===o||c.contains(o))return true; return false; }
   cloneNode(d) { const e=new El(this.tagName.toLowerCase()); Object.assign(e.attributes,this.attributes); e.id=this.id; e.className=this.className; e.classList._sync(this.className); for(const k of Object.keys(this.style)){if(typeof this.style[k]!=='function')e.style[k]=this.style[k];} e.textContent=this.textContent; e.innerHTML=this.innerHTML; e.value=this.value; if(d)for(const c of this.children)e.appendChild(c.cloneNode(true)); return e; }
   focus(){} blur(){} click(){this.dispatchEvent(new Ev('click',{bubbles:true}));} remove(){if(this.parentElement)this.parentElement.removeChild(this);}
+  get nextSibling(){const p=this.parentElement;if(!p)return null;const i=p.children.indexOf(this);return i>=0&&i<p.children.length-1?p.children[i+1]:null;}
+  get nextElementSibling(){return this.nextSibling;}
+  get previousSibling(){const p=this.parentElement;if(!p)return null;const i=p.children.indexOf(this);return i>0?p.children[i-1]:null;}
+  get previousElementSibling(){return this.previousSibling;}
   reset(){
     // Form reset: walk descendants, restore defaultValue / defaultChecked /
     // defaultSelected.

tests/playwright/generate-sx-tests.py

@@ -1071,6 +1071,26 @@ def parse_dev_body(body, elements, var_names):
             ops.append(f'(dom-dispatch {target} "{m.group(3)}" {detail_expr})')
             continue
 
+        # [const X = await ]evaluate(() => { const el = document.querySelector(SEL); el.dispatchEvent(new Event(NAME, ...)); return ... })
+        # Dispatches an event on a queried element and ignores the return value.
+        # Stmt may have trailing un-split junk (`expect(...).toBe(...)`) since
+        # body splitter only breaks on `;` and `})` doesn't always have one.
+        m = re.match(
+            r"(?:const\s+\w+\s*=\s*(?:await\s+)?)?"
+            r"evaluate\(\s*\(\)\s*=>\s*\{\s*"
+            r"const\s+(\w+)\s*=\s*document\.querySelector\(\s*(['\"])([^'\"]+)\2\s*\)\s*;?\s*"
+            r"\1\.dispatchEvent\(\s*new\s+(?:Custom)?Event\(\s*(['\"])([^'\"]+)\4"
+            r"(\s*,\s*\{[^}]*\})?\s*\)\s*\)\s*;?",
+            stmt_na, re.DOTALL,
+        )
+        if m and seen_html:
+            sel = re.sub(r'^#work-area\s+', '', m.group(3))
+            target = selector_to_sx(sel, elements, var_names)
+            opts = m.group(6) or ''
+            detail_expr = _extract_detail_expr(opts)
+            ops.append(f'(dom-dispatch {target} "{m.group(5)}" {detail_expr})')
+            continue
+
         # evaluate(() => document.getElementById(ID).METHOD()) — generic
         # method dispatch (showModal, close, click, focus, blur, reset…).
         m = re.match(