feat(mcp): add verifier latency observer - #497

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/

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