Backend:
- Add ChangePasswordReq DTO with validation (current + new password)
- Add AuthService::change_password() method with credential verification,
password rehash, and token revocation
- Add POST /api/v1/auth/change-password endpoint with utoipa annotation
Frontend:
- Add changePassword() API function in auth.ts
- Add ChangePassword.tsx page with form validation and confirmation
- Add "修改密码" tab in Settings page
After password change, all refresh tokens are revoked and the user
is redirected to the login page.
- Replace non-existent PaletteOutlined with BgColorsOutlined
- Apply user's refined light/dark theme configuration with proper
color tokens, component overrides, and design system consistency
