feat: batch update - gift card breakdown spec, backend APIs, miniprogram pages, ETL finance recharge, docs & migrations

apps/DEMO-miniprogram/miniprogram/components/dev-fab/dev-fab.wxml

@@ -0,0 +1,15 @@
+<!--
+  开发调试浮动按钮 — 仅 develop 环境渲染
+  可拖拽，点击跳转到 dev-tools 页面
+-->
+<movable-area wx:if="{{visible}}" class="fab-area">
+  <movable-view
+    class="fab-btn"
+    direction="all"
+    x="{{x}}"
+    y="{{y}}"
+    bindtap="goDevTools"
+  >
+    <text class="fab-icon">🛠</text>
+  </movable-view>
+</movable-area>