Update fetch for static page gen, fix DOM patching

go/wasmruntime/reconcile.go

@@ -129,10 +129,22 @@ func patch(parent js.Value, o, x *vdom.VNode) {
 		updateEvents(o, x)
 		if x.HTML != "" {
 			if x.HTML != o.HTML {
+				// innerHTML discards whatever DOM the old children owned, so their
+				// listeners go with it.
+				for _, c := range o.Children {
+					release(c)
+				}
 				dom.Set("innerHTML", x.HTML)
 			}
 			return
 		}
+		// o was raw HTML and x isn't. A Raw node keeps its markup only in the DOM
+		// (VNode.HTML, no Children), so patchChildren below would diff x's children
+		// against an empty list and *append* them after markup nothing will ever
+		// remove — e.g. /chart's SVG surviving a route change into /data. Clear it.
+		if o.HTML != "" {
+			dom.Set("innerHTML", "")
+		}
 		patchChildren(dom, o.Children, x.Children)
 	}
 }