feat(V2): /health/ready con ping client + middleware request log strutturato + request_id correlation

- /health/ready: ping di tutti i client (exchange, env) cached con
  timeout 2s, status ready|degraded|not_ready, opt-in 503 via
  READY_FAILS_ON_DEGRADED.
- Middleware mcp.request: 1 riga JSON per HTTP request con request_id,
  method, path, status_code, duration_ms, actor, bot_tag, exchange,
  tool, client_ip, user_agent.
- request_id propagato in request.state, audit log e error envelope per
  correlazione cross-cutting.
- Aggiunto async health() come probe minimo a bybit/alpaca/macro/
  sentiment/deribit (hyperliquid lo aveva già).

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

tests/unit/test_request_log.py

@@ -0,0 +1,121 @@
+from __future__ import annotations
+
+import logging
+
+import pytest
+from fastapi.testclient import TestClient
+from starlette.requests import Request as StarletteRequest
+
+
+@pytest.fixture
+def app(monkeypatch):
+    from tests.unit.test_settings import _minimal_env
+    for k, v in _minimal_env().items():
+        monkeypatch.setenv(k, v)
+    from cerbero_mcp.__main__ import _make_app
+    from cerbero_mcp.settings import Settings
+    return _make_app(Settings())
+
+
+@pytest.fixture
+def request_log_caplog(caplog):
+    """Caplog per logger mcp.request: aggiunge l'handler caplog direttamente
+    al logger, bypassando ``propagate=False`` settato da common/logging.py.
+    """
+    lg = logging.getLogger("mcp.request")
+    lg.addHandler(caplog.handler)
+    lg.setLevel(logging.INFO)
+    caplog.set_level(logging.INFO, logger="mcp.request")
+    try:
+        yield caplog
+    finally:
+        lg.removeHandler(caplog.handler)
+
+
+def _request_records(caplog):
+    return [rec for rec in caplog.records if rec.name == "mcp.request"]
+
+
+def test_request_log_emits_for_health(app, request_log_caplog):
+    c = TestClient(app)
+    r = c.get("/health")
+    assert r.status_code == 200
+    records = _request_records(request_log_caplog)
+    assert any(getattr(rec, "path", None) == "/health" for rec in records)
+
+
+def test_request_log_includes_request_id(app, request_log_caplog):
+    c = TestClient(app)
+    c.get("/health")
+    records = _request_records(request_log_caplog)
+    assert records, "expected at least one mcp.request record"
+    for rec in records:
+        rid = getattr(rec, "request_id", None)
+        assert rid and isinstance(rid, str) and len(rid) >= 16
+
+
+def test_request_log_includes_method_status_duration(app, request_log_caplog):
+    c = TestClient(app)
+    c.get("/health")
+    records = _request_records(request_log_caplog)
+    rec = next(rec for rec in records if getattr(rec, "path", None) == "/health")
+    assert getattr(rec, "method", None) == "GET"
+    assert getattr(rec, "status_code", None) == 200
+    assert isinstance(getattr(rec, "duration_ms", None), int | float)
+
+
+def test_request_log_includes_actor_and_bot_tag_on_protected(
+    app, request_log_caplog
+):
+    """Su path autenticato actor/bot_tag/exchange/tool sono propagati."""
+    c = TestClient(app)
+    c.post(
+        "/mcp-deribit/tools/is_testnet",
+        headers={
+            "Authorization": "Bearer t_test_123",
+            "X-Bot-Tag": "scanner-x",
+        },
+        json={},
+    )
+    records = _request_records(request_log_caplog)
+    rec = next(
+        rec
+        for rec in records
+        if getattr(rec, "path", None) == "/mcp-deribit/tools/is_testnet"
+    )
+    assert getattr(rec, "actor", None) == "testnet"
+    assert getattr(rec, "bot_tag", None) == "scanner-x"
+    assert getattr(rec, "exchange", None) == "deribit"
+    assert getattr(rec, "tool", None) == "is_testnet"
+
+
+def test_request_log_unauthorized_does_not_have_actor(
+    app, request_log_caplog
+):
+    """Senza bearer, request log emette comunque ma senza actor/bot_tag."""
+    c = TestClient(app)
+    c.post("/mcp-deribit/tools/is_testnet", json={})
+    records = _request_records(request_log_caplog)
+    rec = next(
+        rec
+        for rec in records
+        if getattr(rec, "path", None) == "/mcp-deribit/tools/is_testnet"
+    )
+    assert getattr(rec, "status_code", None) == 401
+    assert getattr(rec, "actor", None) is None
+    assert getattr(rec, "exchange", None) == "deribit"
+
+
+def test_request_id_in_state_for_handlers(app):
+    """Verifica che request.state.request_id sia disponibile a handler."""
+    @app.get("/__test_state")
+    def _state_handler(request: StarletteRequest) -> dict:
+        return {"rid": request.state.request_id}
+
+    c = TestClient(app)
+    r = c.get(
+        "/__test_state",
+        headers={"Authorization": "Bearer t_test_123", "X-Bot-Tag": "x"},
+    )
+    assert r.status_code == 200, f"got {r.status_code}: {r.text[:500]}"
+    assert r.json()["rid"]