migrate to the new tiered structure

example/.safeclaude/hooks/10-ruby.sh

@@ -0,0 +1,31 @@
+#!/bin/bash
+# Sets up rbenv and the project's Ruby. Safe to run every launch — it only does
+# real work the first time, or when the Ruby version changes.
+set -euo pipefail
+
+# Grab rbenv (cloned into the home folder so it sticks around between runs).
+if [ ! -d "$RBENV_ROOT/bin" ]; then
+  echo "[ruby] installing rbenv..."
+  git clone --depth=1 https://github.com/rbenv/rbenv.git "$RBENV_ROOT"
+  git clone --depth=1 https://github.com/rbenv/ruby-build.git "$RBENV_ROOT/plugins/ruby-build"
+fi
+eval "$(rbenv init - bash)"
+
+# Pick the Ruby version: the project's .ruby-version wins, then whatever rbenv
+# was last set to, then a sensible default.
+if [ -f /code/.ruby-version ]; then
+  RUBY_VERSION="$(tr -d '[:space:]' < /code/.ruby-version)"
+elif [ -f "$RBENV_ROOT/version" ]; then
+  RUBY_VERSION="$(cat "$RBENV_ROOT/version")"
+else
+  RUBY_VERSION="3.3.6"
+fi
+
+if ! rbenv versions --bare 2>/dev/null | grep -qx "$RUBY_VERSION"; then
+  echo "[ruby] installing Ruby $RUBY_VERSION (first time only — takes a few minutes)..."
+  rbenv install "$RUBY_VERSION"
+fi
+rbenv global "$RUBY_VERSION"
+
+# Make sure bundler is installed for this Ruby.
+gem list bundler -i &>/dev/null || gem install bundler --no-document