Summary

• align SDL3 fullscreen transition timing with final render resolution application in both Generals and Zero Hour display paths
• synchronize non-Windows backbuffer/present sizing and pillarbox fit using active present/backbuffer dimensions as source of truth
• keep fullscreen resize handling robust during transition/reset and remove temporary fullscreen debug instrumentation
• update development diary and lessons with root cause and validated behavior

Validation

• built successfully with task [macOS] Build GeneralsXZH
• runtime validation on affected macOS machine confirmed fullscreen no longer shows top-left zoom/stretch artifact after transition

Notes

• no gameplay logic changes; scope remains rendering/device/window-mode synchronization
• target branch: main