- Add P3 section to phases/phase-100/README.md - Document allowed form: out = out + ch (Variable RHS only) - List Fail-Fast cases (Literal RHS, MethodCall RHS, non-string-ish) - Add example with length-based output 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>