perf(motion): 第三批入场动效时长收敛至 300ms（9 文件 20 处）

承接前两批，继续清理 Task #16 的 P0 硬违规：

- brand-content (1) / methodology-content (3) / products-content-v3 (4) /
  solution-detail-content-v3 (4) / team-content-v3 (1) / detail-product-value (2) /
  service-value (1) / solution-value (3) / brand-visuals 入场处 (1)
- 审计：P0 33 → 13，P1 163 / P2 28 持平
- 只改 duration，保留原 delay（与首批先例一致）

验证：
- tsc --noEmit 0 error；eslint 9 文件 0 error（仅 methodology 既有 `any` 警告，非本次引入）
- 视觉基线不变：前两批已证明时长改动在 reducedMotion+animations disabled 下不改变最终像素

剩余 13 处 P0 均为决策点，未在本批处理：
- 3 处循环动画（detail-hero ×2、brand-visuals ×1，repeat:Infinity，违反「禁循环动画」）
- 10 处死代码（src/lib/animations.tsx，全站零引用）

src/app/(marketing)/methodology/methodology-content.tsx

@@ -34,7 +34,7 @@ export function MethodologyContent({ data }: MethodologyContentProps) {
             <motion.div
               initial={{ opacity: 0, y: 30 }}
               animate={{ opacity: 1, y: 0 }}
-              transition={{ duration: 0.8, delay: 0.1, ease: EASE_OUT }}
+              transition={{ duration: 0.3, delay: 0.1, ease: EASE_OUT }}
               className="inline-flex items-center gap-2 px-3 py-1.5 text-xs font-bold text-brand bg-brand/10 mb-8"
             >
               {heroSubtitle}
@@ -42,7 +42,7 @@ export function MethodologyContent({ data }: MethodologyContentProps) {
             <motion.h1
               initial={{ opacity: 0, y: 40 }}
               animate={{ opacity: 1, y: 0 }}
-              transition={{ duration: 0.9, delay: 0.2, ease: EASE_OUT }}
+              transition={{ duration: 0.3, delay: 0.2, ease: EASE_OUT }}
               className="text-4xl sm:text-5xl md:text-6xl lg:text-7xl font-bold text-ink leading-[1.05] tracking-tight mb-8 whitespace-pre-line"
             >
               {heroTitle}
@@ -50,7 +50,7 @@ export function MethodologyContent({ data }: MethodologyContentProps) {
             <motion.p
               initial={{ opacity: 0, y: 30 }}
               animate={{ opacity: 1, y: 0 }}
-              transition={{ duration: 0.8, delay: 0.35, ease: EASE_OUT }}
+              transition={{ duration: 0.3, delay: 0.35, ease: EASE_OUT }}
               className="text-lg sm:text-xl text-text-secondary max-w-2xl leading-relaxed"
             >
               {heroDescription}