feat: 完善报销单审批流程及退回原因追踪

新增直属领导审批通过接口和审批待办列表查询，报销单退回
支持原因码分类和审批环节标记，优化票据附件去重和路径
回退查找，前端新增退回原因对话框、审批收件箱和工作台
图标组件，补充工具函数和单元测试覆盖。

web/src/components/shared/WorkbenchListIcon.vue

@@ -0,0 +1,107 @@
+<template>
+  <div
+    class="workbench-list-icon"
+    :class="[`workbench-list-icon--${iconKey}`, `workbench-list-icon--${iconStyle}`]"
+    :style="{ '--icon-color': color, '--icon-accent': accent || color }"
+  >
+    <span class="workbench-list-icon__halo" aria-hidden="true"></span>
+    <span class="workbench-list-icon__panel" aria-hidden="true">
+      <span class="workbench-list-icon__shine" aria-hidden="true"></span>
+      <span class="workbench-list-icon__art" aria-hidden="true" v-html="iconMarkup"></span>
+    </span>
+  </div>
+</template>
+
+<script setup>
+import { computed } from 'vue'
+
+import { workbenchIconMap } from '../../utils/workbenchIconAssets.js'
+
+const props = defineProps({
+  iconKey: { type: String, required: true },
+  color: { type: String, default: '#10b981' },
+  accent: { type: String, default: '' }
+})
+
+const iconMeta = computed(() => workbenchIconMap[props.iconKey] || workbenchIconMap.hospitality)
+const iconMarkup = computed(() => iconMeta.value.markup)
+const iconStyle = computed(() => iconMeta.value.style)
+</script>
+
+<style scoped>
+.workbench-list-icon {
+  position: relative;
+  width: 56px;
+  height: 56px;
+  flex-shrink: 0;
+  color: var(--icon-color);
+}
+
+.workbench-list-icon__halo {
+  position: absolute;
+  inset: -3px;
+  border-radius: 20px;
+  background: radial-gradient(
+    circle at 50% 40%,
+    color-mix(in srgb, var(--icon-accent, var(--icon-color)) 42%, transparent) 0%,
+    transparent 72%
+  );
+  opacity: 0.9;
+}
+
+.workbench-list-icon__panel {
+  position: relative;
+  z-index: 1;
+  width: 100%;
+  height: 100%;
+  display: grid;
+  place-items: center;
+  overflow: hidden;
+  border-radius: 18px;
+  border: 1px solid color-mix(in srgb, var(--icon-color) 20%, #e2e8f0);
+  background:
+    radial-gradient(circle at 24% 16%, rgba(255, 255, 255, 0.98), transparent 46%),
+    linear-gradient(
+      160deg,
+      color-mix(in srgb, var(--icon-accent, var(--icon-color)) 24%, #fff) 0%,
+      #fff 42%,
+      color-mix(in srgb, var(--icon-color) 6%, #f8fafc) 100%
+    );
+  box-shadow:
+    inset 0 1px 0 rgba(255, 255, 255, 0.98),
+    0 1px 2px rgba(15, 23, 42, 0.04),
+    0 12px 24px color-mix(in srgb, var(--icon-color) 14%, transparent);
+}
+
+.workbench-list-icon__shine {
+  position: absolute;
+  inset: 0;
+  background: linear-gradient(180deg, rgba(255, 255, 255, 0.55), transparent 38%);
+  pointer-events: none;
+}
+
+.workbench-list-icon__art {
+  position: relative;
+  z-index: 1;
+  display: grid;
+  place-items: center;
+  width: 30px;
+  height: 30px;
+}
+
+.workbench-list-icon__art :deep(.workbench-heroicon) {
+  width: 30px;
+  height: 30px;
+  display: block;
+  color: var(--icon-color);
+  filter: drop-shadow(0 2px 6px color-mix(in srgb, var(--icon-color) 22%, transparent));
+}
+
+.workbench-list-icon--outline .workbench-list-icon__art :deep(.workbench-heroicon) {
+  stroke-width: 1.65;
+}
+
+.workbench-list-icon--solid .workbench-list-icon__art :deep(.workbench-heroicon path) {
+  opacity: 0.96;
+}
+</style>