feat: 落地UI动效——表单错误抖动/数字滚动/卡片悬浮

- 新增styles/transitions.css: 错误shake/按钮状态/弹窗过渡/骨架屏淡入(带prefers-reduced-motion)
- 新增CountUp.vue: KPI数字滚动组件(easeOutCubic+千分位+闪烁提示)
- Dashboard: CEO/IT视图摘要卡片接入CountUp
- main.ts引入全局动效

frontend/src/components/CountUp.vue

@@ -0,0 +1,77 @@
+<template>
+  <span class="cma-count-up" :class="{ 'is-flashing': flashing }" ref="elRef">
+    {{ displayValue }}
+  </span>
+</template>
+
+<script setup lang="ts">
+import { ref, onMounted, onBeforeUnmount, watch, computed } from 'vue'
+
+const props = withDefaults(defineProps<{
+  /** 目标数值 */
+  value: number
+  /** 小数位 */
+  decimals?: number
+  /** 是否加千分位 */
+  thousand?: boolean
+  /** 动画时长 ms */
+  duration?: number
+  /** 前缀 */
+  prefix?: string
+  /** 后缀 */
+  suffix?: string
+}>(), {
+  decimals: 0,
+  thousand: false,
+  duration: 800,
+  prefix: '',
+  suffix: '',
+})
+
+const displayValue = ref(props.prefix + format(props.value) + props.suffix)
+const elRef = ref<HTMLElement | null>(null)
+const flashing = ref(false)
+let rafId: number | null = null
+let lastVal = props.value
+
+function format(n: number): string {
+  const fixed = n.toFixed(props.decimals)
+  if (!props.thousand) return fixed
+  const [int, dec] = fixed.split('.')
+  const withComma = int.replace(/\B(?=(\d{3})+(?!\d))/g, ',')
+  return dec ? `${withComma}.${dec}` : withComma
+}
+
+function animate(from: number, to: number) {
+  if (rafId) cancelAnimationFrame(rafId)
+  if (from === to) {
+    displayValue.value = props.prefix + format(to) + props.suffix
+    return
+  }
+  const start = performance.now()
+  const diff = to - from
+  const tick = (now: number) => {
+    const t = Math.min((now - start) / props.duration, 1)
+    // easeOutCubic
+    const eased = 1 - Math.pow(1 - t, 3)
+    const val = from + diff * eased
+    displayValue.value = props.prefix + format(val) + props.suffix
+    if (t < 1) {
+      rafId = requestAnimationFrame(tick)
+    } else {
+      // 结束闪烁提示
+      flashing.value = true
+      setTimeout(() => { flashing.value = false }, 600)
+    }
+  }
+  rafId = requestAnimationFrame(tick)
+}
+
+watch(() => props.value, (nv, ov) => {
+  animate(ov ?? 0, nv)
+  lastVal = nv
+})
+
+onMounted(() => { lastVal = props.value })
+onBeforeUnmount(() => { if (rafId) cancelAnimationFrame(rafId) })
+</script>