feat(theme): 暗黑模式 Phase 2 批次 2 — services/service-detail/solution-value token 化

将 services-content-v3（7 处）、service-detail-content-v4（7 处）、
solution-value（1 处）的浅色 bg-white 全部迁移到 bg-bg-primary。
浅色下值完全等价（#FFFFFF）→ 浅色视觉零差异；dark 下随 token 自动
反色为 #0A0E14，section 间 bg-bg-secondary 层次交替保留。

【变更】
- services-content-v3.tsx（7 处）：Hero + section + 卡片×3 + main wrapper
  （含卡片条件 className 中两个 bg-white 分支）
- service-detail-content-v4.tsx（7 处）：Hero + FeaturesSection + 卡片×3 +
  CasesSection + main wrapper
- solution-value.tsx（1 处）：共享 section 组件

【验证】
- type-check 0 / lint 0 errors（127 warnings 既有）
- jest 128 suites / 1623 passed
- 视觉回归 22 passed（含 /services 与 /services/software 浅色快照零 diff）
- computed-style 一次性脚本验证（已删除）：
  dark: /services 与 /services/software 的 html/body/header → #0A0E14
  section 层次 [primary, secondary, primary, secondary] 自动反色正确
  light: 零深色残留

【Phase 2 剩余批次】
- 批次 3：product-detail-content-v3 + products/standalone + detail-hero 共享组件
- 批次 4：admin 全量（user决策：参与暗黑）

src/app/(marketing)/services/service-detail-content-v4.tsx

@@ -14,7 +14,7 @@ function DetailHero({ service }: { service: Service }) {
   const firstBenefit = service.benefits?.[0] || '效率提升 40%';
 
   return (
-    <section className="relative min-h-[85vh] flex items-center overflow-hidden bg-white">
+    <section className="relative min-h-[85vh] flex items-center overflow-hidden bg-bg-primary">
       <div className="max-w-container mx-auto px-4 sm:px-6 lg:px-10 relative z-10 w-full py-28 sm:py-36 md:py-44 lg:py-56">
         <div className="max-w-4xl">
           <motion.h1
@@ -147,7 +147,7 @@ function OverviewSection({ service }: { service: Service }) {
 
 function FeaturesSection({ service }: { service: Service }) {
   return (
-    <section className="relative py-20 sm:py-28 md:py-36 lg:py-44 overflow-hidden bg-white">
+    <section className="relative py-20 sm:py-28 md:py-36 lg:py-44 overflow-hidden bg-bg-primary">
       <div className="max-w-container mx-auto px-4 sm:px-6 lg:px-10">
         <motion.div
           initial={{ opacity: 0, y: 30 }}
@@ -176,7 +176,7 @@ function FeaturesSection({ service }: { service: Service }) {
                 whileInView={{ opacity: 1, y: 0 }}
                 viewport={{ once: true, margin: '-60px' }}
                 transition={{ duration: 0.6, delay: index * 0.06, ease: EASE_OUT }}
-                className="group relative p-8 sm:p-10 transition-all duration-500 hover:bg-bg-secondary hover:shadow-lg hover:-translate-y-1 bg-white"
+                className="group relative p-8 sm:p-10 transition-all duration-500 hover:bg-bg-secondary hover:shadow-lg hover:-translate-y-1 bg-bg-primary"
               >
                 <div className="relative z-10">
                   <Icon className="w-8 h-8 mb-6 text-brand" />
@@ -230,7 +230,7 @@ function ProcessSection({ service }: { service: Service }) {
                 whileInView={{ opacity: 1, y: 0 }}
                 viewport={{ once: true, margin: '-60px' }}
                 transition={{ duration: 0.6, delay: index * 0.08, ease: EASE_OUT }}
-                className="relative group p-6 sm:p-8 bg-white hover:bg-bg-secondary hover:shadow-lg hover:-translate-y-1 transition-all duration-500"
+                className="relative group p-6 sm:p-8 bg-bg-primary hover:bg-bg-secondary hover:shadow-lg hover:-translate-y-1 transition-all duration-500"
               >
                 <div
                   className="w-2 h-2 rounded-full mb-6"
@@ -255,7 +255,7 @@ function CaseStudiesSection({ caseStudies = [] }: { caseStudies?: CaseStudy[] })
   if (caseStudies.length === 0) return null;
 
   return (
-    <section id="cases" className="relative py-20 sm:py-28 md:py-36 lg:py-44 overflow-hidden bg-white">
+    <section id="cases" className="relative py-20 sm:py-28 md:py-36 lg:py-44 overflow-hidden bg-bg-primary">
       <div className="max-w-container mx-auto px-4 sm:px-6 lg:px-10">
         <motion.div
           initial={{ opacity: 0, y: 30 }}
@@ -278,7 +278,7 @@ function CaseStudiesSection({ caseStudies = [] }: { caseStudies?: CaseStudy[] })
               whileInView={{ opacity: 1, y: 0 }}
               viewport={{ once: true, margin: '-60px' }}
               transition={{ duration: 0.6, delay: i * 0.08, ease: EASE_OUT }}
-              className="group relative block p-8 sm:p-10 transition-all duration-500 hover:bg-bg-secondary hover:shadow-lg hover:-translate-y-1 bg-white border border-transparent hover:border-border-primary"
+              className="group relative block p-8 sm:p-10 transition-all duration-500 hover:bg-bg-secondary hover:shadow-lg hover:-translate-y-1 bg-bg-primary border border-transparent hover:border-border-primary"
             >
 
               <div className="relative z-10">
@@ -348,7 +348,7 @@ function CTASection() {
 
 export default function ServiceDetailContentV4({ service }: { service: Service }) {
   return (
-    <main className="min-h-screen bg-white text-ink">
+    <main className="min-h-screen bg-bg-primary text-ink">
       <DetailHero service={service} />
       <OverviewSection service={service} />
       <FeaturesSection service={service} />

src/app/(marketing)/services/services-content-v3.tsx

@@ -81,7 +81,7 @@ function HeroSection({ pageCopy }: { pageCopy?: PageCopy | null }) {
   const ctaSecondary = (pageCopy?.servicesCtaSecondary as string) || '查看产品矩阵';
 
   return (
-    <section className="relative min-h-[85vh] flex items-center overflow-hidden bg-white">
+    <section className="relative min-h-[85vh] flex items-center overflow-hidden bg-bg-primary">
       <div className="max-w-container mx-auto px-4 sm:px-6 lg:px-10 relative z-10 w-full py-28 sm:py-36 md:py-44 lg:py-56">
         <div className="max-w-4xl">
           <motion.h1
@@ -205,7 +205,7 @@ function ServicesGridSection({ services, pageCopy }: { services?: Service[]; pag
               key={service.id}
               data-testid={`service-card-${service.id}`}
               data-featured={i === 0 ? 'true' : 'false'}
-              className={i === 0 ? 'md:col-span-2 bg-white' : 'md:col-span-1 bg-white'}
+              className={i === 0 ? 'md:col-span-2 bg-bg-primary' : 'md:col-span-1 bg-bg-primary'}
               initial={{ opacity: 0, y: 30 }}
               whileInView={{ opacity: 1, y: 0 }}
               viewport={{ once: true, margin: '-60px' }}
@@ -213,7 +213,7 @@ function ServicesGridSection({ services, pageCopy }: { services?: Service[]; pag
             >
               <StaticLink
                 href={`/services/${service.id}`}
-                className="group relative block p-8 sm:p-10 md:p-12 transition-all duration-300 hover:bg-bg-secondary hover:shadow-lg hover:-translate-y-1 bg-white border border-transparent hover:border-border-primary after:absolute after:bottom-0 after:left-0 after:h-0.5 after:w-full after:origin-left after:scale-x-0 after:bg-brand after:transition-transform after:duration-300 group-hover:after:scale-x-100"
+                className="group relative block p-8 sm:p-10 md:p-12 transition-all duration-300 hover:bg-bg-secondary hover:shadow-lg hover:-translate-y-1 bg-bg-primary border border-transparent hover:border-border-primary after:absolute after:bottom-0 after:left-0 after:h-0.5 after:w-full after:origin-left after:scale-x-0 after:bg-brand after:transition-transform after:duration-300 group-hover:after:scale-x-100"
               >
                 <div className="relative z-10">
                   <h3 className="text-xl sm:text-2xl font-bold text-ink group-hover:text-brand transition-colors duration-300 mb-3">
@@ -258,7 +258,7 @@ function ServicesGridSection({ services, pageCopy }: { services?: Service[]; pag
 
 function ProcessModesSection() {
   return (
-    <section className="relative py-20 sm:py-28 md:py-36 lg:py-44 overflow-hidden bg-white">
+    <section className="relative py-20 sm:py-28 md:py-36 lg:py-44 overflow-hidden bg-bg-primary">
       <div className="max-w-container mx-auto px-4 sm:px-6 lg:px-10">
         <div className="grid lg:grid-cols-12 gap-12 sm:gap-16 md:gap-20">
           {/* Process */}
@@ -310,7 +310,7 @@ function ProcessModesSection() {
               {SERVICE_MODES.map((mode) => (
                 <div
                   key={mode.title}
-                  className="group relative p-6 sm:p-7 border border-border-primary bg-white hover:bg-bg-secondary hover:border-brand/20 hover:shadow-md transition-all duration-300"
+                  className="group relative p-6 sm:p-7 border border-border-primary bg-bg-primary hover:bg-bg-secondary hover:border-brand/20 hover:shadow-md transition-all duration-300"
                 >
                   <div className="relative z-10">
                     <h3 className="text-xl font-bold text-ink mb-3 group-hover:text-brand transition-colors duration-300">
@@ -373,7 +373,7 @@ function CTASection({ pageCopy }: { pageCopy?: PageCopy | null }) {
 
 export default function ServicesContentV3({ services, pageCopy }: { services?: Service[]; pageCopy?: PageCopy | null }) {
   return (
-    <main className="bg-white text-ink">
+    <main className="bg-bg-primary text-ink">
       <HeroSection pageCopy={pageCopy} />
       <ServicesGridSection services={services} pageCopy={pageCopy} />
       <ProcessModesSection />

src/components/detail/solution-value.tsx

@@ -15,7 +15,7 @@ interface SolutionValueSectionProps {
 
 export function SolutionValueSection({ solution }: SolutionValueSectionProps) {
   return (
-    <section className="relative bg-white py-20 sm:py-28 md:py-36 overflow-hidden">
+    <section className="relative bg-bg-primary py-20 sm:py-28 md:py-36 overflow-hidden">
       <div className="max-w-container mx-auto px-4 sm:px-6 lg:px-10 relative">
         <motion.div
           initial={{ opacity: 0, y: 32 }}