[UM-CLONE-4] Playwright MCP — accessibility-tree snapshots + MCP server surface

[Delqhi]

Source

• Project: Playwright MCP
• License: Apache-2.0
• Clone mode: code

Feature we want

Microsoft's MCP server exposes browser actions as MCP tools and uses accessibility-tree snapshots (cheaper than vision, more reliable than DOM dumps).

Why we want it

MCP is becoming the integration layer for AI tooling. Native MCP support = instant compatibility with Claude Desktop, Cursor, every MCP client.

Acceptance criteria

• unmask mcp subcommand starts an MCP server (stdio + SSE transports)
• Tools exposed: navigate, click, type, snapshot, extract, observe
• Snapshots use Playwright's aria-snapshot API where possible
• Conformance test against MCP spec
• README section on MCP usage
• PR body cites source repo + commit SHA + license
• THIRD_PARTY_NOTICES.md updated
• Parity test added (proves our clone behaves like source for the relevant case)
• CHANGELOG entry: cloned from Playwright MCP@<sha>

Reference

See COMPETITIVE_STRATEGY.md for the full doctrine.