feat(ui): restore reference mini program and admin design

apps/miniprogram/miniprogram/app.wxss

@@ -1,5 +1,15 @@
 page {
-  /* 乐活公益公众端设计令牌：暖、可信、适老。 */
+  /* Primitive → semantic → component tokens. */
+  --primitive-orange-500: #ff6b35;
+  --primitive-orange-600: #e85220;
+  --primitive-orange-50: #fff5ef;
+  --primitive-green-500: #34ad50;
+  --primitive-blue-500: #2f91ed;
+  --primitive-gray-950: #1f2429;
+  --primitive-gray-600: #687078;
+  --primitive-gray-200: #e8ebee;
+  --primitive-gray-50: #f6f7f8;
+  --primitive-white: #ffffff;
   --color-primary: #f05a28;
   --color-primary-pressed: #d94718;
   --color-primary-soft: #fff0e8;
@@ -12,16 +22,18 @@ page {
   --color-warning: #b76e00;
   --color-warning-soft: #fff6dd;
   --color-danger: #b42318;
-  --color-text: #24211f;
-  --color-text-secondary: #6e6862;
+  --color-text: var(--primitive-gray-950);
+  --color-text-secondary: var(--primitive-gray-600);
   --color-text-tertiary: #918a83;
-  --color-border: #e9e3dd;
-  --color-background: #f7f5f2;
-  --color-surface: #ffffff;
+  --color-border: var(--primitive-gray-200);
+  --color-divider: #f0f1f2;
+  --color-background: var(--primitive-gray-50);
+  --color-surface: var(--primitive-white);
   --radius-sm: 16rpx;
   --radius-md: 24rpx;
   --radius-lg: 32rpx;
   --shadow-card: 0 10rpx 32rpx rgba(91, 62, 45, 0.07);
+  --shadow-hero: 0 16rpx 38rpx rgba(231, 79, 29, 0.22);
   min-height: 100%;
   color: var(--color-text);
   background: var(--color-background);