docs(readme): 拆分中英文架构图并统一配色

[milome]

Summary

• Split the ClawScope architecture diagram into English and Chinese SVG files.
• Kept the original architecture structure while aligning the palette with the OpenClaw Gateway diagram style.
• Updated README references and preview HTML to use the localized diagrams.

Test Plan

• npm test -- --run
• npm run build
• SVG text bounding-box checks for en/zh diagrams