refactor(animations): converge P1 motion durations to ≤300ms target

- 151 scripted + 1 manual duration fixes across 46 files
- framer entrance 0.5/0.6s -> 0.3s
- Tailwind hover -> duration-150, entrance -> duration-300
- preserve flip-clock/page-transition per semantic decision
- design-system.ts dead-code deferred
- P1 violations 156 -> 5; P0 remains 0; OK class 249 -> 400
- verified: tsc clean, eslint 0 errors
- verified: 130/130 jest suites, 1573 passed
- verified: visual regression 46/46 zero-pixel diff

Co-Authored-By: 阿睿 <workbuddy@tencent.com>

src/app/(marketing)/home-content-v15.tsx

@@ -179,7 +179,7 @@ function HeroSection({ heroData }: {
 
   // reduced-motion 守卫：与 ScrollReveal 同范式——reduce 时传空 initial/animate，
   // 元素直接以自然（可见）状态渲染，零位移/淡入；默认（非 reduce，含首帧 null）正常动画。
-  const rise = (y: number, delay: number, duration = 0.35) => ({
+  const rise = (y: number, delay: number, duration = 0.3) => ({
     initial: reduceMotion ? {} : { opacity: 0, y },
     animate: reduceMotion ? {} : { opacity: 1, y: 0 },
     transition: { duration: reduceMotion ? 0 : duration, delay: reduceMotion ? 0 : delay, ease: EASE_OUT },