fix(studio): save retries, mutation queue circuit breaker, save_failure diagnostics (#1366)

* fix(studio): save retries, mutation queue circuit breaker, save_failure diagnostics

Save failures could silently drop user work: code-editor saves fired a single
PUT with no retry, DOM-edit failures drained the whole queue against a failing
server, and several failure paths only logged to the console.

- Retry code-editor saves with exponential backoff instead of dropping the
  edit on the first failed PUT.
- Circuit breaker on the DOM-edit save queue: a failing server pauses the
  queue with a user-visible error state instead of burning every queued
  mutation against it.
- save_failure events now carry error_message, status_code, and source on
  every emission path; style/attribute DOM-edit failures that previously only
  logged to the console now emit telemetry too.
- Route unawaited commitMutation call sites (GSAP drag, property scrubbing,
  undo/redo, text fields) through a safe wrapper that reports failures via
  telemetry instead of unhandledrejection.

Follow-ups (deferred): version/ETag conflict guard on file PUTs, offline
save queue.

* fix(studio): narrow save retry changes for fallow

packages/studio/src/components/SaveQueuePausedBanner.tsx

@@ -0,0 +1,23 @@
+interface SaveQueuePausedBannerProps {
+  message: string;
+  onDismiss: () => void;
+}
+
+/** Alert shown when the DOM-edit save queue circuit breaker pauses persistence. */
+export function SaveQueuePausedBanner({ message, onDismiss }: SaveQueuePausedBannerProps) {
+  return (
+    <div
+      className="absolute left-1/2 top-14 z-[92] flex max-w-[calc(100vw-32px)] -translate-x-1/2 items-center gap-3 rounded-md border border-red-500/30 bg-red-950/85 px-4 py-2 text-[12px] font-medium text-red-100 shadow-lg shadow-black/30"
+      role="alert"
+    >
+      <span>{message}</span>
+      <button
+        type="button"
+        onClick={onDismiss}
+        className="rounded border border-red-300/20 px-2 py-1 text-[11px] text-red-100 transition-colors hover:bg-red-400/10"
+      >
+        Dismiss
+      </button>
+    </div>
+  );
+}