openai/gpt-5.2-chat → A (20:1)

Side A pins the Rust toolchain with required components in rust-toolchain.toml, adds VS Code settings to ensure rust-analyzer uses the project toolchain, and cleans up a duplicate CSS rule while running rustfmt across the workspace—improving build reproducibility and tooling reliability. Side B merely deletes a single unused test function in server/src/dsl.rs, removing coverage without adding functionality.