Find series by name, maker name, a generation's name, or a generation's chassis code. Series names match by normalized substring (width, case, kana), maker names by prefix, chassis codes by substring of the code as written (a slash-joined code is one string, not split). A generation matched by its name or chassis code is listed in matched_models. Returns {query, total, hits: [{series, maker, matched_models}], next_offset} where each series and model carries its public page url; pass the ids in the hits to the other skills. Hits are ranked and cut to fit the response size; when next_offset is not null, call again with offset set to it for the rest. Empty hits means nothing matched the query.