add custom theme, 添加自定义主题

[forcemeter]

Summary

• Add 8 customizable color palettes: Rose, Tech, Indigo, Teal, Violet, Emerald, Amber, and Slate.
• Apply palette tokens consistently across Ant Design, charts, chat, settings, control, memory, skills, and other branded UI elements.
• Move the palette selector to Personal Settings, directly below Language.
• Persist the selected palette locally and keep it independent from light/dark mode.
• Improve color contrast and add accessible icon-only palette controls.
• Preserve existing upstream functionality without merging feature-branch implementation code.

Target branch

• Base is develop (feature / fix — default)
• Base is main (release/* or hotfix/* only)

Type of change

• Bug fix
• New feature
• Breaking change
• Documentation
• Refactor / chore
• Release / hotfix

Test plan

• TypeScript check:
  cd dashboard && ./node_modules/.bin/tsc --noEmit -p tsconfig.json
• ESLint passed for changed TypeScript files.
• Prettier formatting check passed.
• Palette tests passed: 17/17.
• make all passes locally
• Added/updated tests

Full dashboard test run: 328 tests passed; 2 pre-existing timezone-formatting tests failed and are unrelated to this change.

Checklist

• Updated CHANGELOG.md (if user-facing)
• README / docs updated (not needed)

Demo