v0.4.21

• After an upload, scripts/discharge_publish.R (WET_PUBLISH=1) rewrites the publish report's live-build line itself once its anonymous verify passes, so no second BUILD follows a republish (#117). The report now records the md5 of its own tree's parts and of the live parts (wet:::wet_catalog_digest()). PUBLISH uploads a tree only under a committed report naming that tree's md5, and the vignette data scripts refuse a report that names the live commit and part count but describes other parts (#94).