R103
A sidecar doesn't match the contract: cargo stops where a generated type or method no longer fits (with the function's id), a binary built from another contract, an output the output schema rejects, or input serde refuses.
Fix: Fix the Rust to fit the TS declaration, which is the source of truth; .weft/rust/<service>.rs shows what's generated.
Status in weft@0.1.0: reported by weft check.