feat(add InMemorySecrets):

agentic_security/test_dependencies.py

@@ -0,0 +1,15 @@
+from agentic_security.dependencies import InMemorySecrets, get_in_memory_secrets
+
+
+def test_in_memory_secrets():
+    secrets = InMemorySecrets()
+    secrets.set_secret("api_key", "12345")
+    assert secrets.get_secret("api_key") == "12345"
+    assert secrets.get_secret("non_existent_key") is None
+
+
+def test_get_in_memory_secrets():
+    secrets = get_in_memory_secrets()
+    assert isinstance(secrets, InMemorySecrets)
+    secrets.set_secret("token", "abcde")
+    assert secrets.get_secret("token") == "abcde"