refactor: remove all futures-related capabilities

Delete USDT-M futures support since the user's Binance API key does not
support futures trading. This simplifies the CLI to spot-only:

- Remove futures client wrapper (um_futures_client.py)
- Remove futures trade commands and close position logic
- Simplify account service to spot-only (no market_type field)
- Remove futures references from opportunity service
- Update README and tests to reflect spot-only architecture
- Bump version to 2.0.7

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

src/coinhunter/services/trade_service.py

@@ -148,116 +148,3 @@ def execute_spot_trade(
     )
     audit_event("trade_filled", {**_trade_log_payload(intent, payload, status=result["status"]), "response_payload": response})
     return {"trade": result}
-
-
-def execute_futures_trade(
-    config: dict[str, Any],
-    *,
-    side: str,
-    symbol: str,
-    qty: float,
-    order_type: str,
-    price: float | None,
-    reduce_only: bool,
-    dry_run: bool | None,
-    futures_client: Any,
-) -> dict[str, Any]:
-    normalized_symbol = normalize_symbol(symbol)
-    order_type = order_type.upper()
-    side = side.upper()
-    is_dry_run = _default_dry_run(config, dry_run)
-    if qty <= 0:
-        raise RuntimeError("Futures orders require a positive --qty")
-    if order_type == "LIMIT" and price is None:
-        raise RuntimeError("Futures limit orders require --price")
-
-    payload: dict[str, Any] = {
-        "symbol": normalized_symbol,
-        "side": side,
-        "type": order_type,
-        "quantity": qty,
-        "reduceOnly": "true" if reduce_only else "false",
-    }
-    if price is not None:
-        payload["price"] = price
-        payload["timeInForce"] = "GTC"
-
-    intent = TradeIntent(
-        market_type="futures",
-        symbol=normalized_symbol,
-        side=side,
-        order_type=order_type,
-        qty=qty,
-        quote_amount=None,
-        price=price,
-        reduce_only=reduce_only,
-        dry_run=is_dry_run,
-    )
-
-    audit_event("trade_submitted", _trade_log_payload(intent, payload, status="submitted"))
-    if is_dry_run:
-        response = {"dry_run": True, "status": "DRY_RUN", "request": payload}
-        result = asdict(
-            TradeResult(
-                market_type="futures",
-                symbol=normalized_symbol,
-                side=side,
-                order_type=order_type,
-                status="DRY_RUN",
-                dry_run=True,
-                request_payload=payload,
-                response_payload=response,
-            )
-        )
-        audit_event("trade_filled", {**_trade_log_payload(intent, payload, status="DRY_RUN"), "response_payload": response})
-        return {"trade": result}
-
-    try:
-        response = futures_client.new_order(**payload)
-    except Exception as exc:
-        audit_event("trade_failed", _trade_log_payload(intent, payload, status="failed", error=str(exc)))
-        raise RuntimeError(f"Futures order failed: {exc}") from exc
-
-    result = asdict(
-        TradeResult(
-            market_type="futures",
-            symbol=normalized_symbol,
-            side=side,
-            order_type=order_type,
-            status=str(response.get("status", "UNKNOWN")),
-            dry_run=False,
-            request_payload=payload,
-            response_payload=response,
-        )
-    )
-    audit_event("trade_filled", {**_trade_log_payload(intent, payload, status=result["status"]), "response_payload": response})
-    return {"trade": result}
-
-
-def close_futures_position(
-    config: dict[str, Any],
-    *,
-    symbol: str,
-    dry_run: bool | None,
-    futures_client: Any,
-) -> dict[str, Any]:
-    normalized_symbol = normalize_symbol(symbol)
-    positions = futures_client.position_risk(normalized_symbol)
-    target = next((item for item in positions if normalize_symbol(item["symbol"]) == normalized_symbol), None)
-    if target is None:
-        raise RuntimeError(f"No futures position found for {normalized_symbol}")
-    position_amt = float(target.get("positionAmt", 0.0))
-    if position_amt == 0:
-        raise RuntimeError(f"No open futures position for {normalized_symbol}")
-    side = "SELL" if position_amt > 0 else "BUY"
-    return execute_futures_trade(
-        config,
-        side=side,
-        symbol=normalized_symbol,
-        qty=abs(position_amt),
-        order_type="MARKET",
-        price=None,
-        reduce_only=True,
-        dry_run=dry_run,
-        futures_client=futures_client,
-    )