fix(selectors): resolve text to the innermost match and scan the root in both forms

an element's text is its whole subtree's text on web and on ios, so every ancestor of a matching element matched too, up to the root. a match a descendant also makes is now dropped, in internal/hierarchy, in the chrome xpath translation and in the page-side web runtime, so all three resolvers name the same element. a raw attribute now matches on a substring (exact for true/false) the way the docs describe, and tree-level FindBySelector considers the root, so ax.find("id:page") and ax.find({id: "page"}) agree.

internal/verifier/marshal.go

@@ -184,7 +184,7 @@ func findNodeFromJS(runtime *goja.Runtime, tree *hierarchy.Tree, arg goja.Value)
 		return nil
 	}
 	requireKnownSelectorKeys(runtime, tree, sel)
-	return tree.Root.FindBySelector(sel)
+	return tree.FindBySelector(sel)
 }
 
 // findAllNodesFromJS dispatches a JS value to Tree-level multi-node lookup.
@@ -204,7 +204,7 @@ func findAllNodesFromJS(runtime *goja.Runtime, tree *hierarchy.Tree, arg goja.Va
 		return nil
 	}
 	requireKnownSelectorKeys(runtime, tree, sel)
-	return tree.Root.FindAllBySelector(sel)
+	return tree.FindAllBySelector(sel)
 }
 
 // findNodeInSubtreeFromJS dispatches a JS value to Node-level scoped lookup.