feat(web): add read-only dashboard server and query layer

reaction_board/web/static/index.html

@@ -0,0 +1,13 @@
+<!doctype html>
+<html lang="zh-CN">
+<head>
+  <meta charset="utf-8">
+  <meta name="viewport" content="width=device-width, initial-scale=1">
+  <title>咻咻满 Reaction 看板</title>
+  <link rel="stylesheet" href="/static/style.css">
+</head>
+<body>
+  <div id="app">正在加载…</div>
+  <script type="module" src="/static/app.js"></script>
+</body>
+</html>