feat(ui): finished turns keep their tool tree, reasoning and say bubbles, the thread stops dragging the reader down

ui/src/lib/panel/markdown.svelte

@@ -7,7 +7,13 @@
     text,
     class: className = "",
     eager = true,
-  }: { text: string; class?: string; eager?: boolean } = $props();
+    inert = false,
+  }: {
+    text: string;
+    class?: string;
+    eager?: boolean;
+    inert?: boolean;
+  } = $props();
 
   const NEAR = "1200px";
 
@@ -50,7 +56,7 @@
     const now = (next: string) => {
       dispose?.();
       node.classList.remove("whitespace-pre-wrap");
-      dispose = host.markdown?.(node, next);
+      dispose = host.markdown?.(node, next, { inert });
     };
     const later = (next: string) => {
       pending = next;