chore: ruff py313, conftest unification, audit log, app factory comune

- pyproject.toml: ruff target-version py311 → py313 (auto-fix 42 lint
  warnings via UP rules); aggiunto consider_namespace_packages = true
  che risolve la collisione conftest tra servizi e permette di lanciare
  pytest sull'intera suite cross-servizio.

- mcp_common.audit: nuovo helper audit_write_op() con logger dedicato
  mcp.audit. Wirato su tutti i write endpoint di deribit, bybit, alpaca
  e hyperliquid (place_order, place_combo_order, cancel_*, set_*,
  close_*, transfer_*, switch_*, amend_*) con principal + target +
  payload non-sensibile + result summarizzato.

- mcp_common.app_factory: ExchangeAppSpec + run_exchange_main()
  centralizza il boilerplate dei __main__.py (configure_root_logging,
  fail_fast_if_missing, summarize, load creds, resolve_environment,
  load token store, uvicorn). I 4 __main__.py exchange ridotti da ~60
  LOC ognuno a ~25 LOC dichiarativi. mcp_common.env_validation
  promosso da mcp_deribit (mantenuto re-export shim per back-compat
  test_env_validation).

- 8 test nuovi (4 audit + 4 app_factory). Suite full: 450/450 verdi.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

services/mcp-sentiment/src/mcp_sentiment/__main__.py

@@ -5,7 +5,6 @@ import os
 
 import uvicorn
 from mcp_common.auth import load_token_store_from_files
-
 from mcp_common.logging import configure_root_logging
 
 from mcp_sentiment.server import create_app

services/mcp-sentiment/src/mcp_sentiment/fetchers.py

@@ -336,7 +336,8 @@ async def fetch_funding_rates(asset: str = "BTC") -> dict[str, Any]:
 
 async def fetch_cross_exchange_funding(assets: list[str] | None = None) -> dict[str, Any]:
     """Snapshot multi-asset funding rates con spread e arbitrage detection."""
-    from datetime import UTC, datetime as _dt
+    from datetime import UTC
+    from datetime import datetime as _dt
 
     assets = [a.upper() for a in (assets or ["BTC", "ETH", "SOL"])]
     snapshot: dict[str, dict[str, Any]] = {}

services/mcp-sentiment/src/mcp_sentiment/server.py

@@ -12,9 +12,9 @@ from pydantic import BaseModel
 logger = logging.getLogger(__name__)
 
 from mcp_sentiment.fetchers import (
-    fetch_crypto_news,
     fetch_cointegration_pairs,
     fetch_cross_exchange_funding,
+    fetch_crypto_news,
     fetch_funding_arb_spread,
     fetch_funding_rates,
     fetch_liquidation_heatmap,