Release 1.5.1

[Sportinger]

Summary

• fix black exports for 3D-transformed video layers
• add regression coverage for export layer collection
• update AI planning docs to call out Kling 3.0 and Nano Banana
• include the current FlashBoard integration work now staged for deployment

Verification

• npm run build
• npm run lint
• npm run test -- --pool=threads

Note: plain
pm run test hit transient Vitest fork worker timeouts in this environment; the threaded rerun completed green.