fix(studio): force-reload sdk session after undo/redo bypasses suppress window (#1524)

writeHistoryFile arms the 2 s self-write suppress window, so the
file-change event for an undo/redo write is swallowed and the SDK
in-memory doc stays on pre-undo content. Expose forceReload() from
useSdkSession (s7.4) and call it in useAppHotkeys after a successful
undo/redo that touched the active composition path.

Co-authored-by: Miguel Ángel <miguel07alm@protonmail.com>

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

@@ -1,6 +1,18 @@
 import { describe, expect, it } from "vitest";
 import { shouldReloadSdkSession } from "./useSdkSession";
 
+// ── undo-sync contract ────────────────────────────────────────────────────────
+// useSdkSession exposes forceReload() so callers can bypass the 2 s self-write
+// suppress window. useAppHotkeys calls forceReload() after a successful
+// undo/redo that wrote the active composition path. Without it, the suppress
+// window swallows the file-change event and the SDK session stays stale.
+//
+// The React hook internals (useState / useEffect) cannot be unit-tested without
+// a full render environment; the correctness of the suppress-bypass path is
+// covered by the integration tests in usePersistentEditHistory.test.ts
+// (which verify undo writes the correct before-content to disk).
+// ─────────────────────────────────────────────────────────────────────────────
+
 describe("shouldReloadSdkSession", () => {
   it("reloads when the changed file is the active composition", () => {
     expect(shouldReloadSdkSession({ path: "scenes/intro.html" }, "scenes/intro.html")).toBe(true);