Update WDPA collection_url for protected-planet restructure (#1)

WDPA bucket moved data into a wdpa-december-2025/ subdirectory and
repurposed public-wdpa/stac-collection.json as a 'protected-planet'
parent collection. Apps relying on catalog traversal alone (or pointing
to the old URL) lose the WDPA layer because geo-agent's catalog walk
does not recurse through intermediate Collection nodes (geo-agent#178).

Tracked in boettiger-lab/glen-ops#14.

Author: cboettig

layers-input.json

@@ -53,6 +53,7 @@
     "collections": [
         {
             "collection_id": "wdpa-december-2025",
+            "collection_url": "https://s3-west.nrp-nautilus.io/public-wdpa/wdpa-december-2025/stac-collection.json",
             "assets": [
                 {
                     "id": "wdpa-pmtiles",