Add stealth MCP server and replace playwright-mcp

[DimmKirr]

Changes

• chore(Dockerfile.tmpl): change flake.nix copy path from home-manager to devcell config
• chore(environment_test.go): update test paths to reflect new devcell config directory
• feat(nixhome/modules/desktop): add stealthInitScript with JS patches to spoof browser fingerprints
• feat(nixhome/modules/desktop): replace playwright-mcp with patchright-mcp in managedMcp servers and wrapper script
• chore(nixhome/modules/desktop): set XRDP max_bpp and xserverbpp to 24 for better color depth
• test(desktop_test.go): add tests verifying patchright-mcp-cell binary, stealth init-script, and wrapper correctness
• test(mcp_test.go): replace all playwright-mcp-cell references with patchright-mcp-cell and add new stealth detection e2e test verifying stealth patches and browser undetectability
• fix(internal/runner): change runner to parse .env and pass env vars individually, resolving self-references by passing -e KEY for Docker inheritance
• chore(internal/runner): add config volume bind for ~/.config/devcell
• chore(images/Dockerfile): update /opt/devcell/.config path to devcell; ensure directory creation and ownership
• chore(images/package.json): replace playwright-mcp dependency with patchright-mcp to support stealth patches