feat(cockpit): run low-latency controls in foreground

[x-lixu]

Summary

• route vehicle state, window, and headlight tools through the foreground MCP surface
• keep one cockpit service executor while removing duplicate backend exposure
• simplify frontend MCP/OpenAPI execution to an explicit allowlist without a Gateway-specific approval layer
• preserve standard MCP annotations as metadata and keep backend Agent permissions unchanged
• carry cockpit identity into the default frontend MCP endpoint

Validation

• npm test
• npm run lint
• npm run test:smart-cockpit
• npm run example:smart-cockpit:build
• npm run docs:build