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

scripts/start.ps1

@@ -0,0 +1,106 @@
+# 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.
+
+[CmdletBinding()]
+param(
+    [int]$Port = 8000,
+    [switch]$NoOpen = $false
+)
+
+$ErrorActionPreference = "Continue"
+[Console]::OutputEncoding = [System.Text.Encoding]::UTF8
+
+$ScriptDir = Split-Path -Parent $MyInvocation.MyCommand.Definition
+$RootDir = Split-Path -Parent $ScriptDir
+Set-Location $RootDir
+
+Write-Host "======================================================" -ForegroundColor Cyan
+Write-Host "      ✨ Artemis Autonomous Mobile Agent UI          " -ForegroundColor Cyan
+Write-Host "======================================================" -ForegroundColor Cyan
+Write-Host ""
+
+function Update-EnvironmentPath {
+    $standardDirs = @(
+        "$env:LOCALAPPDATA\Microsoft\WinGet\Links",
+        "$env:LOCALAPPDATA\Android\Sdk\platform-tools",
+        "$env:ProgramFiles\Android\platform-tools",
+        "C:\ProgramData\chocolatey\bin",
+        "$env:USERPROFILE\scoop\shims",
+        "$env:USERPROFILE\.local\bin",
+        "$env:USERPROFILE\.cargo\bin"
+    )
+    $regPath = [Environment]::GetEnvironmentVariable("Path", "User") + ";" + [Environment]::GetEnvironmentVariable("Path", "Machine")
+    $currentPaths = ($env:PATH -split ";") + ($regPath -split ";") + $standardDirs | Where-Object { [string]::IsNullOrWhiteSpace($_) -eq $false -and (Test-Path $_) } | Select-Object -Unique
+    $env:PATH = $currentPaths -join ";"
+}
+
+function Test-CommandExists {
+    param([string]$Command)
+    $res = Get-Command $Command -ErrorAction SilentlyContinue
+    return ($null -ne $res)
+}
+
+# 1. Refresh PATH with standard toolchain paths
+Update-EnvironmentPath
+
+# 2. Check or install uv
+if (-not (Test-CommandExists "uv")) {
+    Write-Host "⚡ uv not found. Installing Astral uv..." -ForegroundColor Yellow
+    powershell -ExecutionPolicy ByPass -c "irm https://astral.sh/uv/install.ps1 | iex"
+    Update-EnvironmentPath
+}
+
+# 3. Check and try installing missing system toolchains (ADB, FFmpeg, scrcpy)
+$missingCore = @()
+if (-not (Test-CommandExists "adb")) { $missingCore += "adb" }
+if (-not (Test-CommandExists "ffmpeg")) { $missingCore += "ffmpeg" }
+if (-not (Test-CommandExists "scrcpy")) { $missingCore += "scrcpy" }
+
+if ($missingCore.Count -gt 0) {
+    if (Test-CommandExists "winget") {
+        Write-Host "⚡ Auto-installing missing components ($($missingCore -join ', '))..." -ForegroundColor DarkYellow
+        if ($missingCore -contains "adb") {
+            winget install --id Google.PlatformTools -e --accept-source-agreements --accept-package-agreements --silent 2>$null | Out-Null
+        }
+        if ($missingCore -contains "ffmpeg") {
+            winget install --id Gyan.FFmpeg -e --accept-source-agreements --accept-package-agreements --silent 2>$null | Out-Null
+        }
+        if ($missingCore -contains "scrcpy") {
+            winget install --id Genymobile.scrcpy -e --accept-source-agreements --accept-package-agreements --silent 2>$null | Out-Null
+        }
+        Update-EnvironmentPath
+    }
+}
+
+# 4. Check or initialize .env
+if (-not (Test-Path ".env")) {
+    if (Test-Path ".env.example") {
+        Copy-Item ".env.example" ".env"
+        Write-Host "   ✔ Initialized .env configuration file." -ForegroundColor Green
+    } else {
+        New-Item -ItemType File -Path ".env" | Out-Null
+    }
+}
+
+# 5. Synchronize dependencies
+Write-Host "   📦 Synchronizing Python runtime and project dependencies..." -ForegroundColor Cyan
+uv sync --quiet
+
+# 6. Launch unified Showcase UI & open browser
+Write-Host "   🚀 Launching Artemis Showcase UI & Admin Console..." -ForegroundColor Green
+if ($NoOpen) {
+    uv run artemis ui --port $Port --no-open
+} else {
+    uv run artemis ui --port $Port --open
+}