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

mcp_server/server.py

@@ -0,0 +1,69 @@
+# 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.
+
+"""Universal Model Context Protocol (MCP) Server for ARTEMIS."""
+
+import datetime
+import os
+import sys
+
+# Ensure repository root is in sys.path
+PROJECT_ROOT = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
+if PROJECT_ROOT not in sys.path:
+    sys.path.insert(0, PROJECT_ROOT)
+
+# Debug logging and stderr tee to capture crashes without breaking MCP stdio JSON-RPC
+try:
+    _mcp_log_dir = os.path.join(PROJECT_ROOT, "scratch")
+    os.makedirs(_mcp_log_dir, exist_ok=True)
+
+    with open(os.path.join(_mcp_log_dir, "mcp_launch_debug.log"), "a", encoding="utf-8") as _f:
+        _f.write(
+            f"[{datetime.datetime.now()}] Artemis MCP Server launched! sys.argv: {sys.argv}, CWD: {os.getcwd()}\n"
+        )
+
+    class StderrTee:
+        def __init__(self, original, log_path):
+            self.original = original
+            self.log_file = open(log_path, "a", encoding="utf-8")
+
+        def write(self, data):
+            self.original.write(data)
+            self.log_file.write(data)
+            self.log_file.flush()
+
+        def flush(self):
+            self.original.flush()
+            self.log_file.flush()
+
+    sys.stderr = StderrTee(sys.stderr, os.path.join(_mcp_log_dir, "mcp_stderr.log"))
+except Exception:
+    pass
+
+# 1. Import shared FastMCP instance
+from mcp_server.base import mcp
+
+# 2. Import tools to register them
+
+
+def main(transport: str = "stdio", host: str = "127.0.0.1", port: int = 8001):
+    """Main entrypoint to run the Artemis Mobile Agent MCP server."""
+    if transport.lower() == "sse":
+        mcp.run(transport="sse", host=host, port=port)
+    else:
+        mcp.run(transport="stdio")
+
+
+if __name__ == "__main__":
+    main()