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/App.tsx

@@ -3,6 +3,7 @@ import type { LeftSidebarHandle, SidebarTab } from "./components/sidebar/LeftSid
 import { useRenderQueue } from "./components/renders/useRenderQueue";
 import { usePlayerStore } from "./player";
 import { LintModal } from "./components/LintModal";
+import { SaveQueuePausedBanner } from "./components/SaveQueuePausedBanner";
 import { useCaptionStore } from "./captions/store";
 import { useCaptionSync } from "./captions/hooks/useCaptionSync";
 import { usePersistentEditHistory } from "./hooks/usePersistentEditHistory";
@@ -478,6 +479,13 @@ export function StudioApp() {
                 onExport={() => void renderQueue.startRender()}
               />
 
+              {previewPersistence.domEditSaveQueuePaused && (
+                <SaveQueuePausedBanner
+                  message={previewPersistence.domEditSaveQueuePaused}
+                  onDismiss={previewPersistence.resetDomEditSaveQueueBreaker}
+                />
+              )}
+
               <div className="flex flex-1 min-h-0">
                 <StudioLeftSidebar
                   leftSidebarRef={leftSidebarRef}