fix(theme): 4 个亮色派生 #49deff/#4dffc0/#06d2ff/#0affa9 改为 Element mix() 算法
之前 HSL +35% 提亮算法生成荧光色 (例 #49deff / #4dffc0),
对政务/严肃网站完全不适用, 跟 Element Plus 默认色系也对不上.
新算法 (浅色) = Element Plus mix(white, base, N*10%):
--brand-primary-light = mix 50% white (背景 / disabled)
--brand-primary-lighter = mix 70% white (hover-bg / 选中态)
--brand-primary-text = mix 30% white (链接默认)
--brand-primary-mix = mix 80% white (输入框 focus border)
新色 (全是低饱和度灰蓝/灰绿, 跟 Element 默认同源):
PRIMARY (#007A95):
light #80bdca lighter #4da2b5
text #b3d7df mix #3395aa
SECONDARY (#009963):
light #80ccb1 lighter #4db892
text #b3e0d0 mix #33ad82
深色 (deep/darker) 保持 HSL 算法不变 (合理, 政务场景需要深色 hover)
theme.js derivePalette 同步改成双轨: HSL 调深 + Element mix 调浅
郭庆泰
746e9e01b4