## Summary
- allow local marketplace `source.path: "."` and `source.path: "./"` to
resolve to the marketplace root
- keep `""` invalid and preserve rejection of non-root paths without
`./` plus non-normal/traversal paths
- add focused regression coverage for repo-root plugin layouts and
rejected local paths
## Tests
- `RUSTUP_TOOLCHAIN=stable just fmt`
- `RUSTUP_TOOLCHAIN=stable just test -p codex-core-plugins`
- `RUSTUP_TOOLCHAIN=stable just fix -p codex-core-plugins`
Note: plain pinned-toolchain `just fmt` was blocked locally by a rustup
`clippy` component conflict, so validation used the working stable 1.95
toolchain fallback.
Casey ChowandGitHub
a760b63f83