Hardening round 2: healthcheck, audit anchor, return_4h, exec config, signals

Sei interventi MEDIA priorità sul sistema. 323 test pass, mypy strict
pulito, ruff clean.

1. Docker HEALTHCHECK + cerbero-bite healthcheck:
   - nuovo subcommand che esce 0 se kill_switch=0 e last_health_check
     entro --max-staleness-s (default 600s);
   - HEALTHCHECK direttiva nel Dockerfile (60s interval, 5s timeout,
     start_period 120s, retries 3);
   - healthcheck definition nel docker-compose.yml.

2. Audit hash chain anti-truncation:
   - migration 0002: nuova colonna system_state.last_audit_hash;
   - AuditLog accetta callback on_append, dependencies.py la wire al
     repository.set_last_audit_hash;
   - Orchestrator.boot verifica che il tail file matcha l'anchor
     persistito; mismatch → kill switch CRITICAL.

3. return_4h bootstrap da deribit get_historical:
   - quando dvol_history è vuoto _fetch_return_4h cade su
     deribit.historical_close (1h candle 4h fa);
   - alert LOW se anche il fallback fallisce.

4. execution.environment + execution.eur_to_usd in strategy.yaml:
   - ExecutionConfig promosso a typed schema con i due campi
     consumati al boot;
   - CLI start preferisce i valori da config; CLI flag overridano
     solo quando differenti dai default.

5. Cycle correlation ID:
   - structlog.contextvars.bind_contextvars in run_entry/run_monitor/
     run_health propaga cycle_id e cycle nei log strutturati.

6. SIGTERM/SIGINT clean shutdown:
   - run_forever installa loop.add_signal_handler per SIGTERM e
     SIGINT; il segnale set()ta un asyncio.Event che termina il
     blocco principale, scheduler.shutdown e ctx.aclose finalizzano.

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

tests/integration/test_audit_anchor.py

@@ -0,0 +1,125 @@
+"""Tests for the audit chain anti-truncation anchor."""
+
+from __future__ import annotations
+
+from datetime import UTC, datetime
+from pathlib import Path
+
+import pytest
+from pytest_httpx import HTTPXMock
+
+from cerbero_bite.config import golden_config
+from cerbero_bite.config.mcp_endpoints import load_endpoints
+from cerbero_bite.runtime import build_runtime
+from cerbero_bite.runtime.orchestrator import Orchestrator
+from cerbero_bite.state import connect
+
+pytestmark = pytest.mark.httpx_mock(assert_all_responses_were_requested=False)
+
+
+def _now() -> datetime:
+    return datetime(2026, 4, 27, 14, 0, tzinfo=UTC)
+
+
+def _build(tmp_path: Path) -> Orchestrator:
+    ctx = build_runtime(
+        cfg=golden_config(),
+        endpoints=load_endpoints(env={}),
+        token="t",
+        db_path=tmp_path / "state.sqlite",
+        audit_path=tmp_path / "audit.log",
+        retry_max=1,
+        clock=_now,
+    )
+    return Orchestrator(
+        ctx,
+        expected_environment="testnet",
+        eur_to_usd=__import__("decimal").Decimal("1.075"),
+    )
+
+
+def _wire_boot_dependencies(httpx_mock: HTTPXMock) -> None:
+    httpx_mock.add_response(
+        url="http://mcp-deribit:9011/tools/environment_info",
+        json={
+            "exchange": "deribit",
+            "environment": "testnet",
+            "source": "env",
+            "env_value": "true",
+            "base_url": "https://test.deribit.com/api/v2",
+            "max_leverage": 3,
+        },
+        is_reusable=True,
+    )
+    httpx_mock.add_response(
+        url="http://mcp-deribit:9011/tools/get_positions",
+        json=[],
+        is_reusable=True,
+    )
+    httpx_mock.add_response(
+        url="http://mcp-macro:9013/tools/get_macro_calendar",
+        json={"events": []},
+        is_reusable=True,
+    )
+    httpx_mock.add_response(
+        url="http://mcp-sentiment:9014/tools/get_cross_exchange_funding",
+        json={"snapshot": {}},
+        is_reusable=True,
+    )
+    httpx_mock.add_response(
+        url="http://mcp-hyperliquid:9012/tools/get_funding_rate",
+        json={"asset": "ETH", "current_funding_rate": 0.0001},
+        is_reusable=True,
+    )
+    httpx_mock.add_response(
+        url="http://mcp-portfolio:9018/tools/get_total_portfolio_value",
+        json={"total_value_eur": 1000.0},
+        is_reusable=True,
+    )
+
+
+@pytest.mark.asyncio
+async def test_audit_anchor_persisted_after_append(tmp_path: Path) -> None:
+    orch = _build(tmp_path)
+    orch.context.audit_log.append(
+        event="TEST",
+        payload={"x": 1},
+        now=_now(),
+    )
+    conn = connect(tmp_path / "state.sqlite")
+    try:
+        state = orch.context.repository.get_system_state(conn)
+    finally:
+        conn.close()
+    assert state is not None
+    assert state.last_audit_hash == orch.context.audit_log.last_hash
+
+
+@pytest.mark.asyncio
+async def test_boot_detects_audit_truncation(
+    tmp_path: Path, httpx_mock: HTTPXMock
+) -> None:
+    orch = _build(tmp_path)
+    # Append three lines so we have something to truncate.
+    for i in range(3):
+        orch.context.audit_log.append(
+            event=f"E{i}", payload={"i": i}, now=_now()
+        )
+
+    # Truncate the file: keep only the first line.
+    audit_path = tmp_path / "audit.log"
+    head = audit_path.read_text(encoding="utf-8").splitlines(keepends=True)[0]
+    audit_path.write_text(head, encoding="utf-8")
+
+    # Rebuild orchestrator (the AuditLog tail-reads the file again).
+    orch = _build(tmp_path)
+
+    _wire_boot_dependencies(httpx_mock)
+    httpx_mock.add_response(
+        url="http://mcp-telegram:9017/tools/notify_system_error",
+        json={"ok": True},
+        is_reusable=True,
+    )
+
+    await orch.boot()
+    assert orch.context.kill_switch.is_armed() is True

tests/integration/test_monitor_cycle.py

@@ -98,6 +98,7 @@ def _wire_market_data(
     *,
     spot: float = 3000.0,
     dvol: float = 50.0,
+    historical_close: float | None = None,
 ) -> None:
     httpx_mock.add_response(
         url="http://mcp-deribit:9011/tools/get_ticker",
@@ -109,6 +110,16 @@ def _wire_market_data(
         json={"currency": "ETH", "latest": dvol, "candles": []},
         is_reusable=True,
     )
+    # Bootstrap fallback for return_4h when dvol_history is empty.
+    httpx_mock.add_response(
+        url="http://mcp-deribit:9011/tools/get_historical",
+        json={
+            "candles": (
+                [{"close": historical_close}] if historical_close is not None else []
+            )
+        },
+        is_reusable=True,
+    )
 
 
 def _wire_position_quotes(