feat(cli): add machine rename command

[Stephanie (stephanieatdedalus)]

Summary

• Add the PRD-required dedalus rename <current> <new-name> command.
• Call PATCH /v1/machines/{id-or-name} without client-side normalization so the server remains the validation source of truth.
• Print the accepted name and canonical immutable machine_id.
• Cover ID/name routing, request body, response handling, and typed server errors.

Delivery stack

1. dedalus-labs/dedalus#5304: database foundation
2. dedalus-labs/dedalus#5305: DCS API, resolver, and canonical OpenAPI contract
3. dedalus-labs/dedalus#5306: dashboard plus the Scalar-published API document
4. This PR: custom top-level rename command

This PR depends on dedalus-labs/dedalus#5305.

Tests

• ./scripts/lint
• ./scripts/test (all Go packages plus Windows cross-compilation)
• Tested against this CLI repository's current OpenAPI contract