~anthropic/claude-sonnet-latest → B (3:1)

Commit A is a tiny one-line config fix that resolves a NameError, useful but narrow in scope. Commit B fixes an off-by-one indexing bug consistently across rpc.rs and garden.rs, updates doc comments to correctly describe 0-based vs 1-based indexing, removes a misleading fallback that masked bugs, and adds regression tests verifying the corrected behavior, giving it broader and more durable impact.