feat(skills): add validated RDK ISP tuning workflow

[1-ztc]

Summary

• add a bundled rdk-isp-tuning skill for mode-scoped ISP JSON tuning, stable-frame capture, fixed-RAW replay limits, quantitative A/B acceptance, deployment, and rollback
• fix rdk-capture-photo to converge and capture in one get_isp_data process with a delayed l burst
• add Chinese matching and safety regression coverage

Validation

• node --test packages/moss-agent/test/rdk-capture-photo.spec.mjs packages/moss-agent/test/rdk-isp-tuning.spec.mjs (7 passed)
• npm run build -w @rdk-moss/agent
• npm run typecheck -w @rdk-moss/agent
• npm run lint
• npm run check:boundaries
• npm run check:hygiene
• full agent suite reached existing real-board YOLOv5 test; that hardware-dependent test failed because the board command exited 1, unrelated to these asset/test changes