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.

backend/app/broker/binance.py

@@ -0,0 +1,75 @@
+from __future__ import annotations
+
+import hashlib
+import hmac
+import time
+from urllib.parse import urlencode
+
+import httpx
+
+from app.broker.base import Broker, Fill
+from app.market.binance import BASE_URL, to_exchange_symbol
+from app.models import OrderSide, utcnow
+
+TESTNET_URL = "https://testnet.binance.vision"
+
+
+class BinanceBroker(Broker):
+    """Live Binance spot market-order execution (requires API credentials)."""
+
+    def __init__(
+        self,
+        api_key: str,
+        api_secret: str,
+        base_url: str = BASE_URL,
+        timeout: float = 10.0,
+    ) -> None:
+        if not api_key or not api_secret:
+            raise ValueError("Binance broker requires EXCHANGE_API_KEY and EXCHANGE_API_SECRET")
+        self.api_key = api_key
+        self.api_secret = api_secret.encode()
+        self._client = httpx.AsyncClient(base_url=base_url, timeout=timeout)
+
+    def _sign(self, params: dict) -> dict:
+        params = {**params, "timestamp": int(time.time() * 1000), "recvWindow": 5000}
+        query = urlencode(params)
+        signature = hmac.new(self.api_secret, query.encode(), hashlib.sha256).hexdigest()
+        return {**params, "signature": signature}
+
+    async def _market_order(self, symbol: str, side: OrderSide, qty: float) -> Fill:
+        params = self._sign(
+            {
+                "symbol": to_exchange_symbol(symbol),
+                "side": side.value.upper(),
+                "type": "MARKET",
+                "quantity": f"{qty:.8f}".rstrip("0").rstrip("."),
+            }
+        )
+        response = await self._client.post(
+            "/api/v3/order",
+            params=params,
+            headers={"X-MBX-APIKEY": self.api_key},
+        )
+        response.raise_for_status()
+        data = response.json()
+        executed = float(data.get("executedQty", qty))
+        quote = float(data.get("cummulativeQuoteQty", 0.0))
+        price = quote / executed if executed else 0.0
+        fee = sum(float(fill.get("commission", 0.0)) for fill in data.get("fills", []))
+        return Fill(
+            symbol=symbol,
+            side=side,
+            qty=executed,
+            price=price,
+            fee=fee,
+            ts=utcnow(),
+        )
+
+    async def buy(self, symbol: str, qty: float, ref_price: float) -> Fill:
+        return await self._market_order(symbol, OrderSide.BUY, qty)
+
+    async def sell(self, symbol: str, qty: float, ref_price: float) -> Fill:
+        return await self._market_order(symbol, OrderSide.SELL, qty)
+
+    async def close(self) -> None:
+        await self._client.aclose()