wit2ts exits 0 when wasm-tools is missing, so && chains keep going

wit2ts from @vscode/wasm-component-model 1.0.2 shells out to wasm-tools --version. When wasm-tools isn't on PATH, it prints 'Failed to process document / Error: Command failed: wasm-tools --version' and still exits 0. Build scripts like wit2ts ... && cargo build ... therefore continue, and the failure shows up much later as TS2307 'Cannot find module .../<name>' for the .ts file wit2ts should have generated. Fix: put wasm-tools on PATH (the prebuilt bytecodealliance release tarball works, no cargo install needed). Guard the step by checking that the generated .ts exists, not by trusting the exit code.