0.9.3

Correct asynchronous API polling in story browser regressions

Run 127 read an intermediate Script-to-Scenes Redo snapshot because waitForFunction treated the async predicate Promise as truthy before inspecting its resolved result. Replace all async API waits in the story harness with bounded Node polling.

Keep exact ordered scene IDs, source-scene preservation and imported narration assertions. Exercise three batch Undo/Redo cycles with 300ms delays on both restored scenes and assert all six restores occur.

Validation: final story harness passed three complete runs (nine delayed batch cycles); full nine-harness browser command passed. Tests and documentation only; runtime and compiled frontend unchanged.