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>

src/coinhunter/binance/spot_client.py

@@ -0,0 +1,75 @@
+"""Thin wrapper around the official Binance Spot connector."""
+
+from __future__ import annotations
+
+from collections.abc import Callable
+from typing import Any
+
+from requests.exceptions import RequestException, SSLError
+
+
+class SpotBinanceClient:
+    def __init__(
+        self,
+        *,
+        api_key: str,
+        api_secret: str,
+        base_url: str,
+        recv_window: int,
+        client: Any | None = None,
+    ) -> None:
+        self.recv_window = recv_window
+        if client is not None:
+            self._client = client
+            return
+        try:
+            from binance.spot import Spot
+        except ModuleNotFoundError as exc:  # pragma: no cover
+            raise RuntimeError("binance-connector is not installed") from exc
+        self._client = Spot(api_key=api_key, api_secret=api_secret, base_url=base_url)
+
+    def _call(self, operation: str, func: Callable[..., Any], *args: Any, **kwargs: Any) -> Any:
+        try:
+            return func(*args, **kwargs)
+        except SSLError as exc:
+            raise RuntimeError(
+                "Binance Spot request failed because TLS certificate verification failed. "
+                "This usually means the local Python trust store is incomplete or a proxy is intercepting HTTPS. "
+                "Update the local CA trust chain or configure the host environment with the correct corporate/root CA."
+            ) from exc
+        except RequestException as exc:
+            raise RuntimeError(f"Binance Spot request failed during {operation}: {exc}") from exc
+
+    def account_info(self) -> dict[str, Any]:
+        return self._call("account info", self._client.account, recvWindow=self.recv_window)  # type: ignore[no-any-return]
+
+    def exchange_info(self, symbol: str | None = None) -> dict[str, Any]:
+        kwargs: dict[str, Any] = {"recvWindow": self.recv_window}
+        if symbol:
+            kwargs["symbol"] = symbol
+        return self._call("exchange info", self._client.exchange_info, **kwargs)  # type: ignore[no-any-return]
+
+    def ticker_24h(self, symbols: list[str] | None = None) -> list[dict[str, Any]]:
+        if not symbols:
+            response = self._call("24h ticker", self._client.ticker_24hr)
+        elif len(symbols) == 1:
+            response = self._call("24h ticker", self._client.ticker_24hr, symbol=symbols[0])
+        else:
+            response = self._call("24h ticker", self._client.ticker_24hr, symbols=symbols)
+        return response if isinstance(response, list) else [response]  # type: ignore[no-any-return]
+
+    def ticker_price(self, symbols: list[str] | None = None) -> list[dict[str, Any]]:
+        if not symbols:
+            response = self._call("ticker price", self._client.ticker_price)
+        elif len(symbols) == 1:
+            response = self._call("ticker price", self._client.ticker_price, symbol=symbols[0])
+        else:
+            response = self._call("ticker price", self._client.ticker_price, symbols=symbols)
+        return response if isinstance(response, list) else [response]  # type: ignore[no-any-return]
+
+    def klines(self, symbol: str, interval: str, limit: int) -> list[list[Any]]:
+        return self._call("klines", self._client.klines, symbol=symbol, interval=interval, limit=limit)  # type: ignore[no-any-return]
+
+    def new_order(self, **kwargs: Any) -> dict[str, Any]:
+        kwargs.setdefault("recvWindow", self.recv_window)
+        return self._call("new order", self._client.new_order, **kwargs)  # type: ignore[no-any-return]