chore: split CI gate from Claude review, fix tool allowlist

[toolpathguy]

Relates to #4

Summary

Fixes the Claude review workflow that was hitting max-turns (30) with 11 permission denials because the allowlist didn't include file-reading tools.

Changes

Architecture: Split into two jobs:

1. ci — runs npm ci, lint, typecheck, test, build as a gate. Fast, cheap, deterministic.
2. review (depends on ci) — Claude only does code review. The prompt explicitly tells it CI already passed.

Allowlist fix: Added the internal tools Claude Code actually uses to read files:

• Read, Grep, Glob, MultiGrep
• Bash(cat:*), Bash(find:*), Bash(ls:*), Bash(head:*), Bash(tail:*), Bash(wc:*)
• Kept Bash(git diff:*) and Bash(git log:*) for diff context

Removed from Claude's scope: All npm/build commands — those run in the ci job now.

Cost impact: Should cut tokens significantly since Claude won't retry denied tools or run expensive build steps. Max turns reduced to 20 (sufficient for pure review).

CLAUDE.md

Updated to note that CI is a separate gate job.