Add protected Windows task authorization

[loonghao]

Summary

• gate the private task issuer behind Windows protected user-presence verification
• bind native confirmation to the exact retained target, scope, origin, expiry, and proposal
• reject model-visible approval text, forged fields, and injected keyboard events
• expose matching MCP status, plugin metadata, and operator documentation

Verification

• 1161 workspace nextest tests passed
• CLI, Clippy, Hakari, layout, documentation, and release policy gates passed
• release build and CLI E2E passed
• release MCP handshake reports available with seven bounded tools and one authorization card