Update manifest.json: increment extension version to 0.1.3 and raise Gecko strict_min_version to 140.0 to publish a new patch release and require a newer Firefox runtime for compatibility.

Bump extension version to 0.1.1 and add a debounced scheduler for injectRatings to reduce duplicate runs (scheduleInjectRatings with a 50ms timer). Add page re-entry listeners (pageshow, focus, visibilitychange) and switch MutationObserver and storage change handlers to use the scheduler. Adjust processRow to properly re-process rows that lost injected columns while still skipping the table header. Update OMDb parsing to return "N/A" for missing ratings (valueOrNotAvailable) and use that for both IMDb and Rotten Tomatoes values.