feat(safety+audit+deploy): consistency_check + audit log file sink + deploy script

#2 Env switch safety:
- mcp_common/environment.py: nuova consistency_check() che previene
  switch accidentali a mainnet. Solleva EnvironmentMismatchError se
  resolved=mainnet senza creds["environment"]="mainnet" esplicito,
  o se declared/resolved mismatch. Override via STRICT_MAINNET=false.
- Wirato in app_factory.run_exchange_main al boot.
- 6 nuovi test consistency.

#3 Audit log persistence:
- mcp_common/audit.py: TimedRotatingFileHandler aggiuntivo se env
  AUDIT_LOG_FILE settato. Rotation midnight UTC, retention 30gg
  default (AUDIT_LOG_BACKUP_DAYS). Format JSONL con SecretsFilter.
- docker-compose.prod.yml: bind mount /var/log/cerbero-mcp + env
  AUDIT_LOG_FILE per i 4 servizi exchange (write endpoints).
- 2 nuovi test file sink.

#1 Deploy script:
- scripts/deploy.sh: idempotente, fa docker login + clone/pull repo +
  copia secrets chmod 600 + crea .env + setup audit dir + pull image
  + up + smoke test pubblico HTTPS.
- DEPLOYMENT.md aggiornato: sezioni 2 (script), 3 (safety mainnet),
  4 (audit log query), renumber sezioni successive.

Test: 488/488 verdi.

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

services/common/tests/test_app_factory.py

@@ -3,6 +3,8 @@ from __future__ import annotations
 import json
 from unittest.mock import MagicMock, patch
 
+import pytest
+
 from mcp_common.app_factory import ExchangeAppSpec, run_exchange_main
 from mcp_common.environment import EnvironmentInfo
 
@@ -75,7 +77,9 @@ def test_run_exchange_main_uses_default_port(tmp_path, monkeypatch):
 
 def test_run_exchange_main_env_var_overrides_creds(tmp_path, monkeypatch):
     creds_file = tmp_path / "creds.json"
-    creds_file.write_text(json.dumps({"testnet": True}))
+    # `environment: mainnet` esplicito perché env var override → mainnet
+    # e consistency_check richiede conferma per evitare switch accidentale.
+    creds_file.write_text(json.dumps({"testnet": True, "environment": "mainnet"}))
     monkeypatch.setenv("TESTEX_CREDENTIALS_FILE", str(creds_file))
     monkeypatch.setenv("TESTEX_TESTNET", "false")
 
@@ -95,6 +99,33 @@ def test_run_exchange_main_env_var_overrides_creds(tmp_path, monkeypatch):
     assert captured["env_info"].source == "env"
 
 
+def test_run_exchange_main_aborts_on_mainnet_without_confirmation(tmp_path, monkeypatch):
+    """Mainnet senza creds['environment']='mainnet' → boot abort fail-fast."""
+    from mcp_common.environment import EnvironmentMismatchError
+    creds_file = tmp_path / "creds.json"
+    creds_file.write_text(json.dumps({"testnet": False}))
+    monkeypatch.setenv("TESTEX_CREDENTIALS_FILE", str(creds_file))
+    monkeypatch.delenv("TESTEX_TESTNET", raising=False)
+    monkeypatch.delenv("STRICT_MAINNET", raising=False)
+
+    spec = _make_spec()
+    with pytest.raises(EnvironmentMismatchError):
+        with patch("mcp_common.app_factory.uvicorn.run"):
+            run_exchange_main(spec)
+
+
+def test_run_exchange_main_strict_mainnet_disabled_via_env(tmp_path, monkeypatch):
+    """STRICT_MAINNET=false permette mainnet senza conferma (warning soltanto)."""
+    creds_file = tmp_path / "creds.json"
+    creds_file.write_text(json.dumps({"testnet": False}))
+    monkeypatch.setenv("TESTEX_CREDENTIALS_FILE", str(creds_file))
+    monkeypatch.setenv("STRICT_MAINNET", "false")
+
+    spec = _make_spec()
+    with patch("mcp_common.app_factory.uvicorn.run"):
+        run_exchange_main(spec)  # non solleva
+
+
 def test_run_exchange_main_missing_creds_file_exits(monkeypatch):
     monkeypatch.delenv("TESTEX_CREDENTIALS_FILE", raising=False)