fix: sort mixed release tags by version

[cbusillo]

Summary

• add a shared local release-tag helper that normalizes every-code-v*, overlay-v*, and v* versions before sorting
• use version-aware tag ordering for legacy Every Code release notes and fork health output
• constrain the current Release workflow previous-tag lookup to plain v* release tags

Validation

• shellcheck scripts/local/release-tag-utils.sh scripts/local/generate-overlay-release-notes.sh scripts/local/fork-health.sh
• ruby -e 'require "yaml"; YAML.load_file(".github/workflows/release.yml"); puts "yaml ok"'\n- git diff --check\n- bash -n scripts/local/release-tag-utils.sh scripts/local/generate-overlay-release-notes.sh scripts/local/fork-health.sh\n- ./scripts/local/fork-health.sh | sed -n '1,14p'\n- ./build-fast.sh