WT-18394 added a fix_btree_size=true config to WT_SESSION::verify that recomputes the size from the btree and rewrites the checkpoint metadata. WT-18395 wires it into the WiredTiger repair entry point as a fix_btree_size sub-command of wiredtiger_repair(). The config is only meant to be enabled through repair; it is exposed on verify so it can be tested in isolation.
This ticket is the server-side half: have mongod call that repair entry point to trigger verify with the btree size fix config and fix database size.