Ralph init

Scaffold or update repo-local Ralph harness. Opt-in only.

Rules

• Only create/update scripts/ralph/ in the current repo.
• If scripts/ralph/ already exists, offer to update (preserves config.env).
• Copy templates from templates/ into scripts/ralph/.
• Copy flowctl and flowctl.py from ${DROID_PLUGIN_ROOT:-${CLAUDE_PLUGIN_ROOT}}/scripts/ into scripts/ralph/.
• Set executable bit on scripts/ralph/ralph.sh, scripts/ralph/ralph_once.sh, and scripts/ralph/flowctl.

Workflow

1. Resolve repo root: git rev-parse --show-toplevel