Decodes a GeoTIFF/COG (https URL or inline base64), reads the selected RGB bands via windowed overview reads, applies a tone-map stretch, and returns a PNG/WebP plus georeference metadata (CRS, bounds, pixel scale) and source stats. Limits: 20 MB source, 2048 px output width. Billed per attempt: payment settles after structural validation, before decode, so decode-time failures (e.g. a bands_rgb band the source lacks) are still charged.