v0.1.31

Outcall v0.1.31

This patch repairs deterministic container release tagging.

Release packaging

• The release workflow now explicitly publishes both the immutable release tag
  and the rolling latest tag when it is dispatched from main.
• The workflow verifies the immutable image manifest before exporting platform
  archives, so a tag mismatch fails before any release archive work begins.

Verification

• Release builds retain the fast archive export path introduced in v0.1.30:
  export each platform from the already-published multi-architecture manifest.
• The container job keeps its duration summary and warning threshold so slow
  cross-platform builds remain visible in the release run.