Move setup/download helpers into scripts/ and update paths

scripts/setup_dirs.sh

@@ -0,0 +1,27 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# Create the default directory layout for GeoData inputs/outputs.
+ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")"/.. && pwd)"
+
+DIRS=(
+  "$ROOT/raw/dgm1"
+  "$ROOT/raw/dop20/jp2"
+  "$ROOT/raw/dop/jp2"
+  "$ROOT/raw/citygml/lod1"
+  "$ROOT/raw/citygml/lod2"
+  "$ROOT/archives/dgm1"
+  "$ROOT/archives/dop20"
+  "$ROOT/archives/citygml/lod1"
+  "$ROOT/archives/citygml/lod2"
+  "$ROOT/work"
+  "$ROOT/export_unity/height_png16"
+  "$ROOT/export_unity/ortho_jpg"
+)
+
+for dir in "${DIRS[@]}"; do
+  mkdir -p "$dir"
+done
+
+echo "Created default directories:"
+printf ' - %s\n' "${DIRS[@]}"