[Pepps233]

Summary

Restore empty [Unreleased] sections after tagging v0.3.3.

Reasoning

Release workflow's next-cycle housekeeping is submitted separately from the immutable release tag.

Changes

• Run the existing release script's addUnreleasedSection generator for all nine project changelogs.
• Add only the heading and blank line; preserve the v0.3.3 release records.

Testing

• git diff --check passed.
• Reviewed all nine diffs: each adds exactly two lines above the existing release header.
• Documentation-only change; no runtime tests required.