suggestErpImportUseCases

Rank the org's inbound use cases against this file's columns — the input to the ranked picker ("matches 6 of your 7 columns"). Reads only the file's first row, not its data. Every eligible use case is returned, including ones matching nothing: the "nothing fits, pick anyway" view needs the full list. Highest match first. CSV only — an xlsx import fails with 400 rather than silently returning zero matches, which would look identical to "we checked and nothing matches".