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

artemis/interfaces/cli/commands/server.py

@@ -15,6 +15,7 @@
 """Server and cloud proxy commands (artemis server)."""
 
 import http.server
+import os
 import socketserver
 import subprocess
 import time
@@ -50,7 +51,7 @@ def get_identity_token() -> str:
 
 
 class CloudRunProxyHandler(http.server.BaseHTTPRequestHandler):
-    target_url: str = "https://artemis-cloud-brain-971929466682.us-central1.run.app"
+    target_url: str = os.getenv("ARTEMIS_CLOUD_URL", "http://127.0.0.1:8000")
 
     def log_message(self, format, *args):
         logger.info(f"[{self.log_date_time_string()}] {format % args}")
@@ -81,7 +82,9 @@ class CloudRunProxyHandler(http.server.BaseHTTPRequestHandler):
         token = get_identity_token()
         if token:
             headers["Authorization"] = f"Bearer {token}"
-        headers["X-Artemis-Token"] = "alice-token"
+        tenant_token = os.getenv("ARTEMIS_TENANT_TOKEN")
+        if tenant_token:
+            headers["X-Artemis-Token"] = tenant_token
 
         content_length = int(self.headers.get("Content-Length", 0))
         body = self.rfile.read(content_length) if content_length > 0 else None
@@ -119,8 +122,10 @@ def web_proxy_command(
     port: Annotated[int, typer.Option("--port", "-p", help="Local port to bind.")] = 8080,
     target: Annotated[
         str,
-        typer.Option("--target", "-t", help="Target Cloud Run URL."),
-    ] = "https://artemis-cloud-brain-971929466682.us-central1.run.app",
+        typer.Option(
+            "--target", "-t", help="Target Artemis Cloud URL.", envvar="ARTEMIS_CLOUD_URL"
+        ),
+    ] = "http://127.0.0.1:8000",
 ) -> None:
     """Start the local authenticated proxy for ARTEMIS Cloud Web Dashboard."""
     CloudRunProxyHandler.target_url = target