Crypto trading bot: engine, brokers, backtester, dashboard, deploy

FastAPI backend with a single-strategy async engine, paper and Binance
brokers, pure-python indicators, a backtester that shares the engine's
portfolio math, and a Vue dashboard with a live WebSocket feed. Adds the
Gitea Actions CI/CD workflow that deploys to Traefik via docker_default.

frontend/index.html

@@ -0,0 +1,12 @@
+<!doctype html>
+<html lang="en" class="dark">
+  <head>
+    <meta charset="UTF-8" />
+    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
+    <title>Crypto Trader</title>
+  </head>
+  <body class="bg-surface text-slate-100">
+    <div id="app"></div>
+    <script type="module" src="/src/main.js"></script>
+  </body>
+</html>