[BryanFRD]

Path ids and slugs went through encodeURIComponent, which leaves . and .. intact, so fetch collapsed them (e.g. restore_release with release_id: ".." hit /sites/acme/restore).

All path interpolation now goes through pathSegment, which throws on . and .. before any request is made. Tests cover the helper and two tools (id and site slug).

Closes #21

[ferrfleet-interne]

This is correct. encodeURIComponent leaves . and .. as they are, so the WHATWG URL parser would have collapsed /sites/acme/releases/../restore. Rejecting both before encoding closes that hole. A %2e%2e input can't slip through either, because the % is encoded to %25.

I searched the repo and every encodeURIComponent path builder under mcp/packages is converted, so none were missed. @ferrlabs/mcp-core has no equivalent helper, so putting it in api-base.ts makes sense. Nothing blocking.