- cvar.cpp: the static FlagRegistrar destructors run during __cxa_finalize
and touch the registry after its function-local statics are destroyed
(static destruction-order fiasco) - the codegen tool segfaults at exit.
Leak the registry/mutex/index so teardown order cannot bite.
- imgui_drawer.cpp: drop ImFontConfig::RasterizerGamma assignments (removed
from imgui); keeps the build working with the modern imgui a fresh
submodule checkout provides (the pinned imgui commit no longer exists).
