chore: release 0.4.6

[osolmaz]

Summary

MLClaw 0.4.6 ships the private-Space approvals fix from #70.
It pins the published openclaw-brokerkit@0.3.2 package and updates the runtime image tag for the release workflow.

What Changed

Only release metadata changes here.
The functional fix already landed and passed review in #70.

• Bump the npm package from 0.4.5 to 0.4.6.
• Update the lockfile package metadata.
• Set the default runtime image to 0.4.6-openclaw-2026.7.1.

Testing

The complete local release gate passes on this exact metadata.

• 317 tests passed; 2 optional live tests skipped.
• 97.92% statement coverage.
• Formatting, lint, typecheck, build, package validation, secret scan, and Slophammer passed.
• Runtime image and generated-Space tests passed with openclaw-brokerkit@0.3.2.

Risks

This is a patch release with no new public CLI or configuration contract.
The publish workflow will rebuild and verify the npm package and multi-platform runtime image from the tagged commit.

Related: #70 and osolmaz/brokerkit#60.