Walks an extracted asset tree and reports per-format counts plus
how many proprietary files have a wowee open-format sidecar.
Lets users (or CI) see at a glance whether asset_extract was run
with --emit-open and how complete the open-format coverage is:
BLP textures : 12340 (12340 PNG sidecar = 100.0% open)
DBC tables : 240 (240 JSON sidecar = 100.0% open)
M2 models : 8500 (0 WOM sidecar = 0.0% open)
...
overall open-format coverage: 41.2%
(run `asset_extract --emit-open` to fill missing sidecars)
Skips _NNN group sub-files when counting WMOs (only the root WMO
ships with a WOB sidecar). The headless CLI is now at 22 commands.
5a816f104c