fix(studio): reconcile external edits before reload (#2993)

* fix(studio): reconcile external edits before reload

* fix(ci): retry transient workspace installs

Make external reload retry behavior honest and isolate reload listeners.

Remove the dead SDK timestamp parameter.

packages/studio/src/hooks/externalFileReloadBus.test.ts

@@ -0,0 +1,34 @@
+import { describe, expect, it, vi } from "vitest";
+import { addExternalFileReloadListener, notifyExternalFileReload } from "./externalFileReloadBus";
+
+describe("external file reload bus", () => {
+  it("lets the sole watcher reload every SDK owner of the changed path", () => {
+    const first = vi.fn();
+    const second = vi.fn();
+    const removeFirst = addExternalFileReloadListener(first);
+    const removeSecond = addExternalFileReloadListener(second);
+
+    notifyExternalFileReload("scenes/card.html");
+    expect(first).toHaveBeenCalledWith("scenes/card.html");
+    expect(second).toHaveBeenCalledWith("scenes/card.html");
+
+    removeFirst();
+    removeSecond();
+  });
+
+  it("isolates a broken listener so later SDK owners still reload", () => {
+    const broken = vi.fn(() => {
+      throw new Error("stale owner");
+    });
+    const healthy = vi.fn();
+    const removeBroken = addExternalFileReloadListener(broken);
+    const removeHealthy = addExternalFileReloadListener(healthy);
+
+    expect(() => notifyExternalFileReload("scenes/card.html")).not.toThrow();
+    expect(broken).toHaveBeenCalledWith("scenes/card.html");
+    expect(healthy).toHaveBeenCalledWith("scenes/card.html");
+
+    removeBroken();
+    removeHealthy();
+  });
+});