~anthropic/claude-sonnet-latest → A (65:35)

Side A fixes a real semantic issue (a silent unwrap_or(0) masking a should-never-happen case) and reconciles a 1-vs-0 indexing inconsistency across rpc.rs, garden.rs, and types docs, backed by new integration test assertions verifying the corrected indices. Side B is almost entirely rustfmt/tooling churn (reformatting examples, toolchain pin, .vscode settings) plus a trivial CSS dedupe, which is useful hygiene but contributes no functional or correctness value.