Behavior: Reads rollup snapshot files from S3 and loads the measurement data into the search index. This is used to restore or rebuild measurement statistics from previously generated snapshots.

Authorization: Requires an authenticated user via the class-level [Authorize] attribute.

Side Effects: Modifies the search index by loading measurement data from S3 rollup snapshots. Existing measurement data in the index may be overwritten.

Error Scenarios: Returns 400 if the rollup snapshot restoration fails or no snapshots are available.