feat(V2): migrazione hyperliquid completa

- exchanges/hyperliquid/{client,leverage_cap,tools}.py
- routers/hyperliquid.py con 16 endpoint /mcp-hyperliquid/tools/*
- builder hyperliquid in exchanges/__init__.py
- test migrati: test_client, test_leverage_cap (skip V1: server_acl, environment_info)
- test builder hyperliquid (testnet vs mainnet base_url)

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

tests/unit/test_exchanges_builder.py

@@ -50,6 +50,27 @@ async def test_build_client_bybit_returns_correct_env(monkeypatch):
     assert c_live.testnet is False
 
 
+@pytest.mark.asyncio
+async def test_build_client_hyperliquid_returns_correct_env(monkeypatch):
+    from tests.unit.test_settings import _minimal_env
+
+    for k, v in _minimal_env().items():
+        monkeypatch.setenv(k, v)
+
+    from cerbero_mcp.settings import Settings
+    from cerbero_mcp.exchanges import build_client
+
+    s = Settings()
+    c_test = await build_client(s, "hyperliquid", "testnet")
+    c_live = await build_client(s, "hyperliquid", "mainnet")
+
+    assert c_test is not c_live
+    assert c_test.testnet is True
+    assert c_live.testnet is False
+    assert "test" in c_test.base_url.lower()
+    assert "test" not in c_live.base_url.lower()
+
+
 @pytest.mark.asyncio
 async def test_build_client_unknown_exchange_raises(monkeypatch):
     from tests.unit.test_settings import _minimal_env