test: add comprehensive unit, integration, and e2e test suites

Introduce complete test coverage for the ARTEMIS platform across multiple layers:
Unit tests: Add tests for agent nodes (Planner, Operator, Validator, Diagnoser, FlashRunner, Explorer), tools, utils (OCR/XML fusion, UI hierarchy), and data engine.
Integration tests: Add live tool verification, reactive runner, IME, and standalone workflow tests.
E2E tests: Add end-to-end scenario tests for media playback and failure recovery flows.
Fixtures & mocks: Add mock inputs (audio, video, screenshot) and test utilities.

tests/unit/test_tools.py

@@ -0,0 +1,70 @@
+# Copyright 2026 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Unit tests for Universal Tool Protocol and Actions."""
+
+import pytest
+from artemis.drivers.mock.mock_driver import MockDeviceDriver
+from artemis.tools.base import ToolRegistry
+import artemis.tools.actions.device_actions  # noqa: F401 - Register action tools
+
+
+@pytest.mark.asyncio
+async def test_tool_registry_registration():
+    """Verify standard device actions are registered in ToolRegistry."""
+    click_tool = ToolRegistry.get("click")
+    assert click_tool is not None
+    assert click_tool.name == "click"
+    assert click_tool.category == "action"
+
+    swipe_tool = ToolRegistry.get("swipe")
+    assert swipe_tool is not None
+    assert swipe_tool.name == "swipe"
+
+
+@pytest.mark.asyncio
+async def test_tool_execution_with_driver():
+    """Verify tool execution correctly dispatches to MockDeviceDriver."""
+    driver = MockDeviceDriver(width=1000, height=2000)
+
+    # Click normalized [500, 500] -> pixel (500, 1000)
+    result = await ToolRegistry.execute("click", {"target": [500, 500]}, driver=driver, ctx=None)
+    assert "Click" in result or "Clicked" in result
+    assert driver.action_history[-1]["action"] == "tap"
+    assert driver.action_history[-1]["x"] == 500
+    assert driver.action_history[-1]["y"] == 1000
+
+    # Swipe cardinal "up"
+    result = await ToolRegistry.execute("swipe", {"action": "up"}, driver=driver, ctx=None)
+    assert "Swipe" in result or "Swiped" in result
+    assert driver.action_history[-1]["action"] == "swipe_direction"
+
+
+def test_tool_to_genai_declaration():
+    """Verify tools export to Google GenAI FunctionDeclaration properly."""
+    declarations = ToolRegistry.get_genai_declarations(["click", "swipe", "input_text"])
+    assert len(declarations) == 3
+
+    decl_names = [d.name for d in declarations]
+    assert "click" in decl_names
+    assert "swipe" in decl_names
+    assert "input_text" in decl_names
+
+
+def test_tool_to_langchain_tool():
+    """Verify tools export to LangChain BaseTool."""
+    lc_tools = ToolRegistry.get_langchain_tools(ctx=None, names=["click", "press_key"])
+    assert len(lc_tools) == 2
+    assert lc_tools[0].name == "click"
+    assert lc_tools[1].name == "press_key"