Batch-query current live quote data

Returns current quote data, one row per ticker. Fields default to price, changesPercentage, change, previousClose, and volume. Numeric quote values are returned as strings to preserve precision semantics in JSON clients. Symbol scope is resolved per account: most accounts resolve SEC filers plus US-listed ETFs and see anything else in meta.unknownSymbols, while accounts provisioned for unrestricted live scope may request any symbol the quote provider knows and always receive an empty meta.unknownSymbols.