refactor(mcp-common): centralize base_url defaults in resolve_environment

Aggiunti kwargs opzionali default_base_url_live / default_base_url_testnet
a resolve_environment. Rimosse 8 chiamate creds.setdefault duplicate dai
4 servizi (alpaca, bybit, deribit, hyperliquid) ora passano gli URL
canonici direttamente al resolver.

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

services/common/src/mcp_common/environment.py

@@ -29,13 +29,18 @@ def resolve_environment(
     env_var: str,
     flag_key: str,
     exchange: str,
+    default_base_url_live: str | None = None,
+    default_base_url_testnet: str | None = None,
 ) -> EnvironmentInfo:
     """Risolvi l'ambiente per un MCP exchange.
 
-    creds: dict letto dal secret JSON. Deve contenere base_url_live e base_url_testnet.
+    creds: dict letto dal secret JSON. Può contenere base_url_live/base_url_testnet
+        per override; in assenza vengono usati i default kwargs.
     env_var: nome della env var di override (es. DERIBIT_TESTNET).
     flag_key: chiave booleana nel secret JSON (es. "testnet" o "paper" per alpaca).
     exchange: nome exchange per logging/info.
+    default_base_url_live / default_base_url_testnet: URL canonici dell'exchange,
+        applicati se non presenti in creds.
     """
     env_value = os.environ.get(env_var)
     if env_value is not None:
@@ -49,6 +54,11 @@ def resolve_environment(
         environment = "testnet"
         source = "default"
 
+    if default_base_url_live is not None:
+        creds.setdefault("base_url_live", default_base_url_live)
+    if default_base_url_testnet is not None:
+        creds.setdefault("base_url_testnet", default_base_url_testnet)
+
     base_url = creds["base_url_testnet"] if environment == "testnet" else creds["base_url_live"]
     return EnvironmentInfo(
         exchange=exchange,

services/common/tests/test_environment.py

@@ -74,6 +74,37 @@ def test_env_value_truthy_parsing(monkeypatch, raw, expected):
     assert info.environment == expected
 
 
+def test_default_base_urls_applied_when_creds_missing(monkeypatch):
+    monkeypatch.delenv("X_TESTNET", raising=False)
+    creds: dict = {}
+    info = resolve_environment(
+        creds,
+        env_var="X_TESTNET",
+        flag_key="testnet",
+        exchange="x",
+        default_base_url_live="https://live.example",
+        default_base_url_testnet="https://test.example",
+    )
+    assert info.base_url == "https://test.example"
+    assert creds["base_url_live"] == "https://live.example"
+    assert creds["base_url_testnet"] == "https://test.example"
+
+
+def test_creds_base_urls_override_defaults(monkeypatch):
+    monkeypatch.delenv("X_TESTNET", raising=False)
+    creds = {"base_url_live": "L", "base_url_testnet": "T"}
+    info = resolve_environment(
+        creds,
+        env_var="X_TESTNET",
+        flag_key="testnet",
+        exchange="x",
+        default_base_url_live="https://live.example",
+        default_base_url_testnet="https://test.example",
+    )
+    assert info.base_url == "T"
+    assert creds["base_url_live"] == "L"
+
+
 def test_alpaca_paper_flag_key(monkeypatch):
     """Alpaca usa 'paper' invece di 'testnet' nel secret."""
     monkeypatch.delenv("ALPACA_PAPER", raising=False)