refactor: rewrite to CoinHunter V2 flat architecture

Replace the V1 commands/services split with a flat, direct architecture:
- cli.py dispatches directly to service functions
- New services: account, market, trade, opportunity
- Thin Binance wrappers: spot_client, um_futures_client
- Add audit logging, runtime paths, and TOML config
- Remove legacy V1 code: commands/, precheck, review engine, smart executor
- Add ruff + mypy toolchain and fix edge cases in trade params

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

tests/test_trade_service.py

@@ -0,0 +1,124 @@
+"""Trade execution tests."""
+
+from __future__ import annotations
+
+import unittest
+from unittest.mock import patch
+
+from coinhunter.services import trade_service
+
+
+class FakeSpotClient:
+    def __init__(self):
+        self.calls = []
+
+    def new_order(self, **kwargs):
+        self.calls.append(kwargs)
+        return {"symbol": kwargs["symbol"], "status": "FILLED", "orderId": 1}
+
+
+class FakeFuturesClient:
+    def __init__(self):
+        self.calls = []
+
+    def new_order(self, **kwargs):
+        self.calls.append(kwargs)
+        return {"symbol": kwargs["symbol"], "status": "FILLED", "orderId": 2}
+
+    def position_risk(self, symbol=None):
+        return [{"symbol": "BTCUSDT", "positionAmt": "-0.02", "notional": "-1200"}]
+
+
+class TradeServiceTestCase(unittest.TestCase):
+    def test_spot_market_buy_dry_run_does_not_call_client(self):
+        events = []
+        with patch.object(trade_service, "audit_event", side_effect=lambda event, payload: events.append((event, payload))):
+            client = FakeSpotClient()
+            payload = trade_service.execute_spot_trade(
+                {"trading": {"dry_run_default": False}},
+                side="buy",
+                symbol="btc/usdt",
+                qty=None,
+                quote=100,
+                order_type="market",
+                price=None,
+                dry_run=True,
+                spot_client=client,
+            )
+        self.assertEqual(payload["trade"]["status"], "DRY_RUN")
+        self.assertEqual(client.calls, [])
+        self.assertEqual([event for event, _ in events], ["trade_submitted", "trade_filled"])
+
+    def test_spot_limit_sell_maps_payload(self):
+        with patch.object(trade_service, "audit_event", return_value=None):
+            client = FakeSpotClient()
+            payload = trade_service.execute_spot_trade(
+                {"trading": {"dry_run_default": False}},
+                side="sell",
+                symbol="BTCUSDT",
+                qty=0.1,
+                quote=None,
+                order_type="limit",
+                price=90000,
+                dry_run=False,
+                spot_client=client,
+            )
+        self.assertEqual(payload["trade"]["status"], "FILLED")
+        self.assertEqual(client.calls[0]["timeInForce"], "GTC")
+
+    def test_futures_close_uses_opposite_side(self):
+        with patch.object(trade_service, "audit_event", return_value=None):
+            client = FakeFuturesClient()
+            payload = trade_service.close_futures_position(
+                {"trading": {"dry_run_default": False}},
+                symbol="BTCUSDT",
+                dry_run=False,
+                futures_client=client,
+            )
+        self.assertEqual(payload["trade"]["side"], "BUY")
+        self.assertEqual(client.calls[0]["reduceOnly"], "true")
+
+    def test_spot_market_buy_requires_quote(self):
+        with patch.object(trade_service, "audit_event", return_value=None):
+            with self.assertRaisesRegex(RuntimeError, "requires --quote"):
+                trade_service.execute_spot_trade(
+                    {"trading": {"dry_run_default": False}},
+                    side="buy",
+                    symbol="BTCUSDT",
+                    qty=None,
+                    quote=None,
+                    order_type="market",
+                    price=None,
+                    dry_run=False,
+                    spot_client=FakeSpotClient(),
+                )
+
+    def test_spot_market_buy_rejects_qty(self):
+        with patch.object(trade_service, "audit_event", return_value=None):
+            with self.assertRaisesRegex(RuntimeError, "accepts --quote only"):
+                trade_service.execute_spot_trade(
+                    {"trading": {"dry_run_default": False}},
+                    side="buy",
+                    symbol="BTCUSDT",
+                    qty=0.1,
+                    quote=100,
+                    order_type="market",
+                    price=None,
+                    dry_run=False,
+                    spot_client=FakeSpotClient(),
+                )
+
+    def test_spot_market_sell_rejects_quote(self):
+        with patch.object(trade_service, "audit_event", return_value=None):
+            with self.assertRaisesRegex(RuntimeError, "accepts --qty only"):
+                trade_service.execute_spot_trade(
+                    {"trading": {"dry_run_default": False}},
+                    side="sell",
+                    symbol="BTCUSDT",
+                    qty=0.1,
+                    quote=100,
+                    order_type="market",
+                    price=None,
+                    dry_run=False,
+                    spot_client=FakeSpotClient(),
+                )