feat: introduce MCP server, cross-platform runtime, and Showcase UI reorganization

- Showcase UI Reorganization:
  * Move web UI dashboard from root directory into apps/showcase_ui/ for cleaner project structure
  * Add 'artemis ui' CLI command (artemis/interfaces/cli/commands/ui.py) and launcher scripts for the interactive showcase console
- Standalone MCP Server & Notifiers (mcp_server/):
  * Implement dedicated MCP server package with mobile automation tools (device_state, inspect_trace, task_manager, task_runner)
  * Add multi-channel notifiers (AgentAPI, Desktop notifications, Webhooks, File output, and Composite routing)
  * Introduce background task runner and trace store for autonomous mobile execution monitoring
- Cross-Platform Runtime & Toolchain Support:
  * Add artemis/platform/ with OS-specific implementations for Linux, macOS (Darwin), and Windows
  * Add artemis/runtime/supervisor.py for resilient process and agent runtime supervision
  * Add artemis/toolchain/ with dependency resolution and SDK descriptors
  * Add cross-platform launcher scripts (start.sh, start.bat) and installer scripts (scripts/install_deps.*)
- Core Enhancements & Diagnostics:
  * Enhance coordinate normalization, OCR API fallback, and perception pipeline
  * Add credential validation (credentials_validator.py) and system diagnostics
  * Update bilingual documentation (README.md, README_CN.md) and architecture diagrams
- Test Suite Expansion:
  * Add integration tests for cloud gateway, remote ADB, and Artemis login
  * Add unit tests covering core diagnostics, platform detection, toolchain, credentials validator, optional OCR, and MCP tools

tests/unit/mcp/test_trace_store.py

@@ -0,0 +1,77 @@
+# 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 MCP trace store."""
+
+import shutil
+import tempfile
+import uuid
+import pytest
+
+from mcp_server.utils import trace_store
+
+
+@pytest.fixture
+def temp_trace_env(monkeypatch):
+    temp_dir = tempfile.mkdtemp()
+    monkeypatch.setattr(trace_store, "TRACES_DIR", temp_dir)
+    yield temp_dir
+    shutil.rmtree(temp_dir, ignore_errors=True)
+
+
+def test_init_and_read_status(temp_trace_env):
+    trace_id = str(uuid.uuid4())
+    task_desc = "Test open settings"
+    model = "Flash"
+    conv_id = "test-conv-123"
+
+    init_res = trace_store.init_trace(trace_id, task_desc, model, conv_id)
+    assert init_res["trace_id"] == trace_id
+    assert init_res["status"] == "running"
+    assert init_res["model"] == "Flash"
+
+    status_data = trace_store.read_status(trace_id)
+    assert status_data is not None
+    assert status_data["trace_id"] == trace_id
+    assert status_data["task_desc"] == task_desc
+    assert status_data["conversation_id"] == conv_id
+
+
+def test_update_trace_status(temp_trace_env):
+    trace_id = str(uuid.uuid4())
+    trace_store.init_trace(trace_id, "Test task", "Pro", "conv-456")
+
+    updated = trace_store.update_trace_status(
+        trace_id=trace_id,
+        status="completed",
+        result={"success": True},
+    )
+    assert updated is not None
+    assert updated["status"] == "completed"
+    assert updated["result"] == {"success": True}
+    assert updated["end_time"] is not None
+
+    failed = trace_store.update_trace_status(
+        trace_id=trace_id,
+        status="failed",
+        error="App crashed",
+    )
+    assert failed is not None
+    assert failed["status"] == "failed"
+    assert failed["error"] == "App crashed"
+
+
+def test_read_nonexistent_status(temp_trace_env):
+    non_existent = str(uuid.uuid4())
+    assert trace_store.read_status(non_existent) is None