The unification flattened BT_STEAM into the always-on exe; the user flagged
the constraint that makes it the one legitimate compile gate: the Steamworks
SDK license bars a public release with Steam inside, so a release build must
exclude it entirely.
- CMakeLists: option(BT_STEAM OFF) restored around the Steamworks block --
an OFF configure touches no SDK headers, no steam_api.lib, no DLL copy.
BT_GLASS stays retired (always defined); ONE build dir either way.
Dev checkout: build/ configured once with -DBT_STEAM=ON.
- mkdist: reads BT_STEAM from build/CMakeCache.txt. Steam-OFF zips exclude
play_steam.bat + steam_api.dll (explicitly filtering a STALE DLL left by
an earlier ON build), strip the README steam section ({STEAM} line
markers), and take a -nosteam name suffix so the flavors never clobber
(found live: both stamped 4.11.436 and the release zip overwrote the dev
zip).
Verified both flavors:
ON (dev build): steam smoke degrades to Winsock without the client;
zip carries play_steam.bat + steam_api.dll + README steam lines.
OFF (scratch build-relcheck, deleted after): 0 compile errors; exe dir =
btl4.exe + OpenAL32.dll only; boots + simulates; BT_STEAM_NET=1 inert
(transport not in the binary); end-to-end zip has zero steam bits and
a clean README.
KB: context/glass-cockpit.md unified-build section records the license gate.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>