Closes the two post-merge failures from #436:
1. wasm-pack: command not found — cargo install doesn't reliably leave
the binary on PATH. Switched to the canonical installer in both the
Pages and a11y workflows.
2. nvsim-server Docker build — cargo couldn't resolve workspace.dependencies
from a partial copy. Dockerfile now generates a stub workspace
Cargo.toml inline that lists just nvsim + nvsim-server.