fix(web-runtime): answer clickable for an element reached through ax

The handle hardcoded true, so every text node and container a spec reached
through state.ax claimed to be a tap target while the enumeration and the
hierarchy dump both resolved it through the tappable selector.

The parity test now compares the handle against the enumeration element by
element in a real browser, which is where the three answers have to agree.

Claude-Session: https://claude.ai/code/session_01A5KmftdEJ49A9z5mF5ESrX

pkg/spec/src/web-runtime.ts

@@ -488,7 +488,10 @@ function elementHandle(element: Element, selector: unknown): Record<string, unkn
     text,
     desc: ariaLabel,
     class: (element as HTMLElement).className ?? "",
-    clickable: true,
+    // The selector collectTargets and the hierarchy dump (driver.go) both
+    // resolve clickable through. Hardcoded true here, every text node and
+    // container a spec reached through state.ax claimed to be a tap target.
+    clickable: element.matches(TAPPABLE_SELECTOR),
     enabled: isEnabled(element),
     editable: isEditableElement(element as HTMLElement),
     focused: document.activeElement === element,