Add command-based worktree provisioning

scripts/provision-worktree.sh

@@ -0,0 +1,37 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+base_cwd="${PAPERCLIP_WORKSPACE_BASE_CWD:?PAPERCLIP_WORKSPACE_BASE_CWD is required}"
+worktree_cwd="${PAPERCLIP_WORKSPACE_CWD:?PAPERCLIP_WORKSPACE_CWD is required}"
+
+if [[ ! -d "$base_cwd" ]]; then
+  echo "Base workspace does not exist: $base_cwd" >&2
+  exit 1
+fi
+
+if [[ ! -d "$worktree_cwd" ]]; then
+  echo "Derived worktree does not exist: $worktree_cwd" >&2
+  exit 1
+fi
+
+while IFS= read -r relative_path; do
+  [[ -n "$relative_path" ]] || continue
+  source_path="$base_cwd/$relative_path"
+  target_path="$worktree_cwd/$relative_path"
+
+  [[ -d "$source_path" ]] || continue
+  [[ -e "$target_path" || -L "$target_path" ]] && continue
+
+  mkdir -p "$(dirname "$target_path")"
+  ln -s "$source_path" "$target_path"
+done < <(
+  cd "$base_cwd" &&
+    find . \
+      -mindepth 1 \
+      -maxdepth 3 \
+      -type d \
+      -name node_modules \
+      ! -path './.git/*' \
+      ! -path './.paperclip/*' \
+      | sed 's#^\./##'
+)