fix(theme): 品牌色令牌语义拆分与暗黑模式全站治理

- 拆分品牌色「文字/底色」双通道：新增 --color-brand-ink(-rgb)（深色 #F87171）
  与 tailwind brand.ink；text-brand → text-brand-ink 迁移 247 处；
  bg-brand/border-brand 保持 --color-brand-rgb 不翻转（红底白字 5.58:1 不能动）
- dark 块补齐 --color-brand-bg: #2A1418（修复深色白字压浅粉底 1.04:1）
- hero 徽章新增 --badge-accent-text 桥接：accentColor 直用作深底文字不可读
  （#1e3a5f 深底 1.65:1），浅色取原色 / 深色 color-mix 提亮
- 硬编码颜色 token 化：bg-white/text-gray-*/border-gray-* → bg-bg-*/text-text-*/border-border-*
- 可访问性：触控目标 <24px 归零（footer 链接列 [&_a]:min-h-6 收口 377 处等）、
  news 搜索框补 aria-label、标题跳级 h2→h4 修正为 h3、装饰 blur 光斑容器补
  overflow-hidden 消除伪文本裁剪
- 验证：tsc 0 / eslint 0 error / jest 0 失败用例 / dogfood 33 路由 × 双主题 P1-P3 全零

src/components/ui/button.tsx

@@ -19,7 +19,7 @@ const buttonVariants = cva(
         ghost:
           'text-text-secondary hover:bg-bg-secondary hover:text-text-primary active:scale-[0.97] transition-all duration-fast ease-standard',
         link:
-          'text-text-primary underline-offset-4 hover:text-brand relative after:absolute after:bottom-0 after:left-0 after:h-[2px] after:w-0 hover:after:w-full after:bg-brand after:transition-all after:duration-normal after:ease-standard',
+          'text-text-primary underline-offset-4 hover:text-brand-ink relative after:absolute after:bottom-0 after:left-0 after:h-[2px] after:w-0 hover:after:w-full after:bg-brand after:transition-all after:duration-normal after:ease-standard',
         destructive:
           'bg-error text-white shadow-sm hover:bg-error-hover hover:-translate-y-px active:translate-y-0 active:scale-[0.97] transition-all duration-fast ease-standard',
       },

src/components/ui/context-menu.tsx

@@ -111,7 +111,7 @@ const ContextMenuCheckboxItem = React.forwardRef<
   >
     <span className="absolute left-2 flex size-3.5 items-center justify-center">
       <ContextMenuPrimitive.ItemIndicator>
-        <Check className="size-4 text-brand" />
+        <Check className="size-4 text-brand-ink" />
       </ContextMenuPrimitive.ItemIndicator>
     </span>
     {children}
@@ -136,7 +136,7 @@ const ContextMenuRadioItem = React.forwardRef<
   >
     <span className="absolute left-2 flex size-3.5 items-center justify-center">
       <ContextMenuPrimitive.ItemIndicator>
-        <Circle className="size-2 fill-brand text-brand" />
+        <Circle className="size-2 fill-brand text-brand-ink" />
       </ContextMenuPrimitive.ItemIndicator>
     </span>
     {children}

src/components/ui/cta-button.tsx

@@ -45,7 +45,7 @@ const VARIANT_STYLES: Record<CTAButtonVariant, string> = {
   dark:
     'text-dark-text-primary border border-dark-border hover:border-dark-text-muted hover:bg-white/5 px-10 py-4 font-semibold text-base',
   inline:
-    'text-text-primary hover:text-brand px-0 py-0 font-medium text-sm bg-transparent border-0',
+    'text-text-primary hover:text-brand-ink px-0 py-0 font-medium text-sm bg-transparent border-0',
 };
 
 const ARROW_STYLES: Record<CTAButtonVariant, string> = {

src/components/ui/dropdown-menu.tsx

@@ -113,7 +113,7 @@ const DropdownMenuCheckboxItem = React.forwardRef<
   >
     <span className="absolute left-2 flex size-3.5 items-center justify-center">
       <DropdownMenuPrimitive.ItemIndicator>
-        <Check className="size-4 text-brand" />
+        <Check className="size-4 text-brand-ink" />
       </DropdownMenuPrimitive.ItemIndicator>
     </span>
     {children}
@@ -138,7 +138,7 @@ const DropdownMenuRadioItem = React.forwardRef<
   >
     <span className="absolute left-2 flex size-3.5 items-center justify-center">
       <DropdownMenuPrimitive.ItemIndicator>
-        <Circle className="size-2 fill-brand text-brand" />
+        <Circle className="size-2 fill-brand text-brand-ink" />
       </DropdownMenuPrimitive.ItemIndicator>
     </span>
     {children}

src/components/ui/labeled-input.tsx

@@ -31,7 +31,7 @@ const LabeledInput = React.forwardRef<HTMLInputElement, LabeledInputProps>(
           >
             {label}
             {required && (
-              <span className="text-brand ml-1.5" aria-hidden="true">*</span>
+              <span className="text-brand-ink ml-1.5" aria-hidden="true">*</span>
             )}
           </Label>
         )}
@@ -56,7 +56,7 @@ const LabeledInput = React.forwardRef<HTMLInputElement, LabeledInputProps>(
         {error && (
           <p
             id={errorId}
-            className="mt-1.5 text-sm text-brand"
+            className="mt-1.5 text-sm text-brand-ink"
             role="alert"
             data-testid="error-message"
           >

src/components/ui/labeled-textarea.tsx

@@ -31,7 +31,7 @@ const LabeledTextarea = React.forwardRef<HTMLTextAreaElement, LabeledTextareaPro
           >
             {label}
             {required && (
-              <span className="text-brand ml-1.5" aria-hidden="true">*</span>
+              <span className="text-brand-ink ml-1.5" aria-hidden="true">*</span>
             )}
           </Label>
         )}
@@ -56,7 +56,7 @@ const LabeledTextarea = React.forwardRef<HTMLTextAreaElement, LabeledTextareaPro
         {error && (
           <p
             id={errorId}
-            className="mt-1.5 text-sm text-brand"
+            className="mt-1.5 text-sm text-brand-ink"
             role="alert"
             data-testid="error-message"
           >

src/components/ui/metric-card.tsx

@@ -26,7 +26,7 @@ interface MetricCardProps {
 }
 
 const accentStyles: Record<string, string> = {
-  brand: 'text-brand bg-brand-bg',
+  brand: 'text-brand-ink bg-brand-bg',
   blue: 'text-accent-blue bg-accent-blue/10',
   teal: 'text-accent-teal bg-accent-teal/10',
   amber: 'text-accent-amber bg-accent-amber/10',

src/components/ui/milestone-timeline.tsx

@@ -68,7 +68,7 @@ export function MilestoneTimeline({
               )}>
                 <div className="w-2 h-2 rounded-full bg-brand" />
               </div>
-              <div className="text-sm font-bold text-brand mb-1 tracking-wider">
+              <div className="text-sm font-bold text-brand-ink mb-1 tracking-wider">
                 {item.year}
               </div>
               <h4 className={cn('text-lg font-semibold mb-2', isDark ? 'text-white' : 'text-text-primary')}>
@@ -80,7 +80,7 @@ export function MilestoneTimeline({
               {item.highlight && (
                 <div className={cn(
                   'mt-3 inline-flex items-center px-3 py-1 rounded-full text-xs font-medium',
-                  isDark ? 'bg-brand/10 text-brand' : 'bg-brand-bg text-brand'
+                  isDark ? 'bg-brand/10 text-brand-ink' : 'bg-brand-bg text-brand-ink'
                 )}>
                   {item.highlight}
                 </div>
@@ -112,7 +112,7 @@ export function MilestoneTimeline({
             )}>
               <div className="w-2 h-2 rounded-full bg-brand" />
             </div>
-            <div className="text-sm font-bold text-brand mb-2 tracking-wider">
+            <div className="text-sm font-bold text-brand-ink mb-2 tracking-wider">
               {item.year}
             </div>
             <h4 className={cn('text-base font-semibold mb-2 leading-snug', isDark ? 'text-white' : 'text-text-primary')}>

src/components/ui/page-decoration.tsx

@@ -36,7 +36,7 @@ export function SectionLabel({
       )}
     >
       <div className="w-10 h-px bg-brand" />
-      <span className="text-[13px] tracking-[0.15em] font-medium text-brand">
+      <span className="text-[13px] tracking-[0.15em] font-medium text-brand-ink">
         {children}
       </span>
     </div>

src/components/ui/radio-group.tsx

@@ -30,7 +30,7 @@ const RadioGroupItem = React.forwardRef<
     ref={ref}
     data-slot="radio-group-item"
     className={cn(
-      'aspect-square size-4 rounded-full border border-border-primary bg-bg-primary text-brand shadow-sm',
+      'aspect-square size-4 rounded-full border border-border-primary bg-bg-primary text-brand-ink shadow-sm',
       'focus:outline-none focus-visible:ring-2 focus-visible:ring-brand focus-visible:ring-offset-2',
       'disabled:cursor-not-allowed disabled:opacity-50',
       'data-[state=checked]:border-brand',
@@ -43,7 +43,7 @@ const RadioGroupItem = React.forwardRef<
       data-slot="radio-group-indicator"
       className="flex items-center justify-center"
     >
-      <Circle className="size-2.5 fill-brand text-brand" />
+      <Circle className="size-2.5 fill-brand text-brand-ink" />
     </RadioGroupPrimitive.Indicator>
   </RadioGroupPrimitive.Item>
 ));

src/components/ui/select.tsx

@@ -133,7 +133,7 @@ const SelectItem = React.forwardRef<
   >
     <span className="absolute right-2 flex size-3.5 items-center justify-center">
       <SelectPrimitive.ItemIndicator>
-        <Check className="size-4 text-brand" />
+        <Check className="size-4 text-brand-ink" />
       </SelectPrimitive.ItemIndicator>
     </span>
     <SelectPrimitive.ItemText>{children}</SelectPrimitive.ItemText>