Socket v6.13.1

What changed

• Refreshed swiftasb-skills for SwiftASB v1.6.0.
• Added guidance for CodexThread.Agenda, plan-mode turn starts, thread goal helpers, and plan/goal diagnostics across the existing SwiftASB skill set.
• Bumped all maintained Socket version surfaces to 6.13.1.

Breaking changes

• None.

Migration/upgrade notes

• Run codex plugin marketplace upgrade socket to refresh an installed Socket marketplace after this release.

Verification performed

• uv run scripts/validate_socket_metadata.py
• uv run pytest
• Temporary CODEX_HOME local marketplace smoke test for swiftasb-skills
• scripts/release.sh release-ready 6.13.1