test(zed): enforce CLI dependency contract

[ORESoftware]

What changed

• preserves the newly merged production-ready CLI Zed manifest, including its build, binary, smoke-test, and publish settings
• adds a deterministic validator requiring exactly leddy-interfaces, leddy-lib, and leddy-clients
• runs the contract check for pull requests and default-branch pushes

Why

The CLI now has the correct Zed package metadata. This follow-up prevents future native/Zed dependency drift without discarding the richer build and publication configuration introduced on main.

Validation

• parses .zpkg.toml using Python tomllib
• rejects missing and unexpected dependencies
• remains additive to existing Rust format, clippy, and test CI