* 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
Vance Ingalls