Two bugs found via headless Claude CLI integration testing:
1. Colormap ID extraction: _detect_colormap returned the layer
identifier as colormap_id, but GIBS layers often share colormaps
under different filenames (e.g., AMSRU2_Sea_Ice_Concentration_12km
-> colormap AMSR2_Sea_Ice_Concentration.xml). Now parses the actual
filename from the metadata xlink:href.
2. Entries wrapper: GIBS v1.3 colormap XML nests ColorMapEntry elements
inside an <Entries> wrapper. The parser only searched direct children
of <ColorMap>, finding zero entries from live data. Now checks
Entries/ColorMapEntry first, falling back to direct children.
Updated test fixture to use the real <Entries> wrapper structure.
Ryan Malloy
31dff49351