fix: hide Honcho session line on CLI load when no API key configured (#1582)

HonchoClientConfig.from_env() set enabled=True unconditionally,
even when HONCHO_API_KEY was not set. When ~/.honcho/config.json
didn't exist, from_global_config() fell back to from_env() and
returned enabled=True with a null api_key, causing the Honcho
session indicator to display on every CLI launch.

Fix: from_env() now sets enabled=bool(api_key), matching the
auto-enable logic already used in from_global_config().
Also added api_key guard to the CLI display as defense-in-depth.

honcho_integration/client.py

@@ -114,11 +114,12 @@ class HonchoClientConfig:
     @classmethod
     def from_env(cls, workspace_id: str = "hermes") -> HonchoClientConfig:
         """Create config from environment variables (fallback)."""
+        api_key = os.environ.get("HONCHO_API_KEY")
         return cls(
             workspace_id=workspace_id,
-            api_key=os.environ.get("HONCHO_API_KEY"),
+            api_key=api_key,
             environment=os.environ.get("HONCHO_ENVIRONMENT", "production"),
-            enabled=True,
+            enabled=bool(api_key),
         )
 
     @classmethod