Clarify the optional TensorRT download

[wimi321]

Summary

• renames the website card from “TensorRT 高性能版” to the neutral “TensorRT 可选版”
• removes RTX 30 from the TensorRT recommendation to avoid misleading users
• recommends the optional package only for RTX 20 / GTX 16, notes the common CUDA speed benefit, and keeps the GTX 10 warning
• updates all seven website languages and adds a regression check

Validation

• git diff --check
• pnpm check:website
• pnpm website:build (46 pages)
• pnpm test (262/262)
• real-browser mobile layout check against the stable catalog