Post apivizrowslookup

POST /viz/rows/lookup — resolve selected point IDs to row dicts.

Accepts {"datasetId": ..., "versionId": ..., "ids": [int, ...]}. Returns {"rows": [{"id": <int>, <visible-field>: <value>, ...}]}. Selection size is capped at MAX_LOOKUP_IDS; out-of-range IDs are silently dropped (the client gets fewer rows than requested).