refactor: migrate to US stocks with Alpaca API

- Replace Binance/ccxt with Alpaca REST client (paper + live)
- Add MOC (Market on Close) strategy for overnight gap trading
- Wire sentiment into strategy engine main loop
- Add EMA + bullish candle entry filters to Asian RSI
- Remove crypto-specific exchange factory
- Update config: Alpaca keys replace Binance keys
- 399 tests passing, lint clean

2 files changed, 12 insertions, 5 deletions

diff --git a/shared/src/shared/alpaca.py b/shared/src/shared/alpaca.py
index 3dd752b..7821592 100644
--- a/shared/src/shared/alpaca.py
+++ b/shared/src/shared/alpaca.py
@@ -1,6 +1,6 @@
 """Alpaca Markets API client for US stock trading."""
+
 import logging
-from datetime import datetime, timezone
 from decimal import Decimal
 from typing import Any
 
@@ -107,7 +107,8 @@ class AlpacaClient:
 
     async def get_orders(self, status: str = "open", limit: int = 50) -> list:
         return await self._request(
-            "GET", f"{self._base_url}/v2/orders",
+            "GET",
+            f"{self._base_url}/v2/orders",
             params={"status": status, "limit": limit},
         )
 
@@ -155,19 +156,23 @@ class AlpacaClient:
             params["end"] = end
 
         data = await self._request(
-            "GET", f"{self._data_url}/v2/stocks/{symbol}/bars", params=params,
+            "GET",
+            f"{self._data_url}/v2/stocks/{symbol}/bars",
+            params=params,
         )
         return data.get("bars", [])
 
     async def get_latest_quote(self, symbol: str) -> dict:
         data = await self._request(
-            "GET", f"{self._data_url}/v2/stocks/{symbol}/quotes/latest",
+            "GET",
+            f"{self._data_url}/v2/stocks/{symbol}/quotes/latest",
         )
         return data.get("quote", {})
 
     async def get_snapshot(self, symbol: str) -> dict:
         return await self._request(
-            "GET", f"{self._data_url}/v2/stocks/{symbol}/snapshot",
+            "GET",
+            f"{self._data_url}/v2/stocks/{symbol}/snapshot",
         )
 
     # --- Market Status ---
diff --git a/shared/tests/test_alpaca.py b/shared/tests/test_alpaca.py
index 7c8eab1..080b7c4 100644
--- a/shared/tests/test_alpaca.py
+++ b/shared/tests/test_alpaca.py
@@ -1,4 +1,5 @@
 """Tests for Alpaca API client."""
+
 import pytest
 from unittest.mock import AsyncMock, MagicMock
 from shared.alpaca import AlpacaClient
@@ -40,6 +41,7 @@ async def test_get_buying_power(client):
 
     result = await client.get_buying_power()
     from decimal import Decimal
+
     assert result == Decimal("10000.00")
     await client.close()