If the scroll-edge fade shader failed to compile or link, the init path
left its ready flag clear and tried again on the very next frame. On a
driver that rejects the shader that meant a fresh compile attempt every
frame, for the life of the program.
- A failed init is now latched and treated as final until destroy(), so
the compile is attempted once, the failure is logged once, and the
fades stay disabled without further retries. Destroying the shader
clears the latch so a later re-init can try again.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>