CWS-95: Remove redundant plugin and curl fallback

• Linear: CWS-95
• Branch: cws/95-remove-remember-plugin
• Priority: Low
• Type: cleanup

Context

Two pieces of infrastructure are redundant and add complexity for zero benefit:

1. Remember plugin (remember@claude-plugins-official) — installed but never used (.remember/remember.md stayed 0 bytes). Built-in auto memory + docs/agent-context.md already provide cross-session continuity.

2. scripts/lib/github-api.sh curl fallback library — was a workaround for gh CLI TLS issues in the Claude Code sandbox. Now that gh auth is fixed, the 332-line curl fallback with Ruby JSON parsing is unnecessary complexity.

Scope

Remember plugin

1. Delete .claude/remember/config.json (tracked)
2. Remove .remember/ gitignore entry
3. Remove Skill(remember) from .claude/settings.local.json allowlist

github-api.sh removal

1. Delete scripts/lib/github-api.sh
2. Refactor scripts/create-pr.sh — direct gh CLI calls
3. Refactor scripts/finalize-merge.sh — direct gh CLI calls
4. Update test assertions in both workflow test files
5. Update .agents/skills/repo-flow/SKILL.md — remove fallback section
6. Update .agents/skills/repo-flow/references/branch-pr-merge.md

Not touched (historical/immutable)

• docs/superpowers/plans/2026-03-22-script-hardening.md
• docs/superpowers/specs/2026-03-22-script-hardening-design.md
• .codex/rollout/evidence/cws-94-fallback-and-flags.md

Out of Scope

• Plugin uninstall command (requires interactive CLI)
• Changes to built-in auto memory configuration