Add DOS Chain token list

[JOY (JOY)]

Summary

• add the DOS Chain Mainnet Uniswap Token List
• add the WDOS icon to the shared token icon directory
• validate schema, canonical asset paths, file existence, and SVG safety in CI

Validation

• official Uniswap Token Lists schema: passed
• actionlint: passed
• git diff --check: passed
• independent review: approved

Existing unrelated issue

• full-repository ESLint reports the pre-existing duplicate author key in configs/marketplace/dos.json