Brief

Fix broken create-pr.sh and finalize-merge.sh scripts after CWS-93 phase removal. Add governance exempt patterns, gh/curl fallback, non-interactive mode, stack merge support, template-driven PR body, agent-context staleness mechanism, and repo-flow skill rewrite.

Design Spec

docs/superpowers/specs/2026-03-22-script-hardening-design.md

Implementation Plan

docs/superpowers/plans/2026-03-22-script-hardening.md

Evidence