fix(banner): show honcho tools as available when configured (#3810)

The honcho check_fn only checked runtime session state, which isn't
set until the agent initializes. At banner time, honcho tools showed
as red/disabled even when properly configured.

Now checks configuration (enabled + api_key/base_url) as a fallback
when the session context isn't active yet. Fast path (session active)
unchanged; slow path (config check) only runs at banner time.

Adds 4 tests covering: session active, configured but no session,
not configured, and import failure graceful fallback.

Closes #1843.

tests/tools/test_honcho_tools.py

@@ -1,11 +1,86 @@
 """Regression tests for per-call Honcho tool session routing."""
 
 import json
-from unittest.mock import MagicMock
+from unittest.mock import MagicMock, patch
+from dataclasses import dataclass
 
 from tools import honcho_tools
 
 
+class TestCheckHonchoAvailable:
+    """Tests for _check_honcho_available (banner + runtime gating)."""
+
+    def setup_method(self):
+        self.orig_manager = honcho_tools._session_manager
+        self.orig_key = honcho_tools._session_key
+
+    def teardown_method(self):
+        honcho_tools._session_manager = self.orig_manager
+        honcho_tools._session_key = self.orig_key
+
+    def test_returns_true_when_session_active(self):
+        """Fast path: session context already injected (mid-conversation)."""
+        honcho_tools._session_manager = MagicMock()
+        honcho_tools._session_key = "test-key"
+        assert honcho_tools._check_honcho_available() is True
+
+    def test_returns_true_when_configured_but_no_session(self):
+        """Slow path: honcho configured but agent not started yet (banner time)."""
+        honcho_tools._session_manager = None
+        honcho_tools._session_key = None
+
+        @dataclass
+        class FakeConfig:
+            enabled: bool = True
+            api_key: str = "test-key"
+            base_url: str = None
+
+        with patch("tools.honcho_tools.HonchoClientConfig", create=True):
+            with patch(
+                "honcho_integration.client.HonchoClientConfig"
+            ) as mock_cls:
+                mock_cls.from_global_config.return_value = FakeConfig()
+                assert honcho_tools._check_honcho_available() is True
+
+    def test_returns_false_when_not_configured(self):
+        """No session, no config: tool genuinely unavailable."""
+        honcho_tools._session_manager = None
+        honcho_tools._session_key = None
+
+        @dataclass
+        class FakeConfig:
+            enabled: bool = False
+            api_key: str = None
+            base_url: str = None
+
+        with patch(
+            "honcho_integration.client.HonchoClientConfig"
+        ) as mock_cls:
+            mock_cls.from_global_config.return_value = FakeConfig()
+            assert honcho_tools._check_honcho_available() is False
+
+    def test_returns_false_when_import_fails(self):
+        """Graceful fallback when honcho_integration not installed."""
+        import sys
+
+        honcho_tools._session_manager = None
+        honcho_tools._session_key = None
+
+        # Hide honcho_integration from the import system to simulate
+        # an environment where the package is not installed.
+        hidden = {
+            k: sys.modules.pop(k)
+            for k in list(sys.modules)
+            if k.startswith("honcho_integration")
+        }
+        try:
+            with patch.dict(sys.modules, {"honcho_integration": None,
+                                          "honcho_integration.client": None}):
+                assert honcho_tools._check_honcho_available() is False
+        finally:
+            sys.modules.update(hidden)
+
+
 class TestHonchoToolSessionContext:
     def setup_method(self):
         self.orig_manager = honcho_tools._session_manager