Count vessels in a SAR scene

Count vessel-like targets in ONE Sentinel-1 or NISAR scene over an area, using CFAR detection. Costs 5 tokens per detection (a NISAR granule converted for the first time adds 1, and needs the plan's NISAR access); a scene the worker refuses (an unsupported combination, an area with no usable sea) is not charged. Get item_id from GET /api/v1/imagery first. Read caveats before quoting the count: it says when the land mask was unavailable (shoreline structures may be counted as vessels), how far from the coast detections were excluded (the default excludes vessels alongside a quay), and when the scene covers only part of the requested area — a partial-coverage count must not be compared with a full one as though the difference were vessels. This measures one scene at one time; to track a berth over time, create a monitored area with metric ships.