fix: preserve annotated tag validation in package workflow

[openai0229]

The first v0.0.1 tag run failed before packaging because actions/checkout rewrites the checked-out tag ref to the tagged commit. The validation step therefore saw a commit object and rejected a correctly annotated tag.

Restore the remote tag object in the validation step before checking its type. This keeps the annotated-tag gate and verifies the tagged commit remains reachable from origin/main.

Validation:

• actionlint .github/workflows/package.yml
• git diff --check
• isolated Git fixture reproducing checkout ref replacement and remote annotated-tag restoration

The failed run was 37721948027; no Release was created and the existing tag is not published. After this PR merges, the failed tag will be recreated on the new main commit and the release workflow rerun.

AI assistance: implementation and verification performed with Codex.