feat: add auto-review skill (local mirror of claude/auto-review CI)

[enesozturk]

What

Adds a new auto-review skill that reproduces the WalletConnect claude/auto-review GitHub Action locally, against the current branch's changes, so issues are caught before a PR is opened. It reads the local git diff instead of the GitHub PR API and prints findings to the terminal.

The existing code-review skill is kept as-is — auto-review is added alongside it.

Why

code-review is generic. auto-review gives a pre-PR preview of exactly what CI's claude/auto-review action will flag — same scope, same checks, same severity/ID output format — so contributors can fix findings before pushing.

Skill contents

skills/auto-review/
├── SKILL.md
├── HEURISTICS.md          # subagent gating rules
├── REVIEW_PROMPT.md       # review scope + 5 automated checks
└── agents/
    ├── review-breaking-changes.md
    ├── review-data-classification.md
    └── review-license-compliance.md

• Parity with CI: same five automated checks (PR size, external-domain URLs, cache-control, GitHub Actions security, WalletConnect Pay architecture) and the three heuristic-gated subagents (breaking-changes, license-compliance, data-classification).
• Read-only, issues-only, severity-ranked output (Critical > High > Medium > Low); ✅ No issues found when clean.
• Subagent spec paths are install-location-relative for portability.

Notes

• This skill is intentionally WalletConnect-specific (external-domain allowlist + WalletConnect Pay architecture check), matching the CI action it mirrors.
• README updated in all three index spots (skills table, Skill Details, directory tree).
• ./scripts/validate.sh → ✓ 20 skills validated, passed.

🤖 Generated with Claude Code