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

.env.example

@@ -1,19 +1,24 @@
 # ==============================================================================
-# ☕ Latte Environment Configuration
+# Artemis Environment Configuration Template
 # ==============================================================================
+# Copy this file to .env and fill in your API credentials:
+# cp .env.example .env
 
-# 1. Primary LLM Provider API Key (Required for Agent Planning & Reasoning)
-GEMINI_API_KEY=your_gemini_api_key_here
+# LLM Providers (Configure at least one)
+GEMINI_API_KEY=
+GOOGLE_API_KEY=
+OPENAI_API_KEY=
+ANTHROPIC_API_KEY=
+OPEN_ROUTER_API_KEY=
+XAI_API_KEY=
 
-# 2. Google Cloud Vision OCR API Key (Required for fast text perception & XML fusion)
-OCR_API_KEY=your_google_cloud_vision_api_key_here
+# Google Cloud Vision OCR (Optional - for advanced OCR processing)
+OCR_API_KEY=
 
-# Optional: Alternative LLM Providers
-# OPENAI_API_KEY=your_openai_api_key_here
-# ANTHROPIC_API_KEY=your_anthropic_api_key_here
-# OPEN_ROUTER_API_KEY=your_openrouter_api_key_here
-# XAI_API_KEY=your_xai_api_key_here
-
-# Optional: Target Android Device Serial (Leave commented for auto-detection)
-# ADB_DEVICE_SERIAL=emulator-5554
+# Android ADB Connectivity (Optional - defaults to 127.0.0.1:5037)
+ADB_HOST=127.0.0.1
+ADB_PORT=5037
+# ADB_DEVICE_SERIAL=
 
+# Artemis Execution Defaults (flash or pro)
+ARTEMIS_DEFAULT_PROFILE=flash