feat(mcp): implement double-insurance global-only MCP and testing rules installation

- Install MCP configs and Artemis mobile testing rules strictly into user home directories (~), avoiding project workspace pollution
- Add double-insurance rules synchronization injecting into both primary global instruction files (e.g. ~/.gemini/GEMINI.md, ~/.claude/CLAUDE.md, ~/.cursorrules, ~/.codeium/windsurf/memories/global_rules.md) and modular rules/ directories
- Support JSONC parsing (comments and trailing commas) and automatic .bak backups when merging existing IDE configuration files
- Update README and Quick Start documentation to clarify automatic global MCP & rule mounting across all major AI IDEs

scripts/start.ps1

@@ -132,11 +132,11 @@ if ((-not (Test-Path $ShowcaseIndex)) -and (-not (Test-Path $ShowcaseIndexAlt1))
 
 # 7. Optionally configure MCP for detected AI IDEs
 Write-Host ""
-Write-Host "   🔌 Would you like to configure ARTEMIS MCP for your AI IDEs?" -ForegroundColor Cyan
+Write-Host "   🔌 Would you like to configure ARTEMIS MCP & testing rules for your AI IDEs?" -ForegroundColor Cyan
 Write-Host "      (Supported: Antigravity, Cursor, Claude Code/Desktop, OpenClaw, Windsurf)"
 $installMcp = "Y"
 if ([Console]::IsInputRedirected -eq $false) {
-    $response = Read-Host "      Install MCP configuration now? [Y/n]"
+    $response = Read-Host "      Install MCP configuration & rules now? [Y/n]"
     if ($response -ne "") {
         $installMcp = $response
     }
@@ -145,7 +145,7 @@ if ([Console]::IsInputRedirected -eq $false) {
 }
 
 if ($installMcp -match "^[Yy]") {
-    Write-Host "   ✔ Installing MCP server configuration..." -ForegroundColor Green
+    Write-Host "   ✔ Installing MCP server configuration & testing rules..." -ForegroundColor Green
     uv run artemis mcp --install all 2>$null | Out-Null
     Write-Host "   💡 Tip: You can update or re-install anytime with: uv run artemis mcp --install all" -ForegroundColor Cyan
 } else {