Fix release workflow npm pack parsing

[jasonsuhari]

Problem

The v0.1.6 release workflow failed in the Pack npm package step after npm emitted JSON in a shape the workflow regex did not parse.

Requested behavior

Parse npm pack JSON structurally in PowerShell so the release workflow accepts both object and array output shapes and can continue to npm publish and GitHub release creation.

Acceptance checks

• Release workflow pack step uses ConvertFrom-Json instead of a brittle regex.
• Both manual and tag release paths are fixed.
• The fixed workflow can publish the existing v0.1.6 tag.

[jasonsuhari]

The first parser fix handled object/array shapes but the Actions runner emitted an object keyed by package name (gridbash.filename). Reopening to add that third shape.

[jasonsuhari]

Release now reaches npm publish, but npm@latest on the Windows runner fails with MODULE_NOT_FOUND for sigstore during
pm publish --provenance. Updating the workflow to use Node 24/npm 11.5+ and the trusted-publishing publish path without explicit --provenance.