Add repository storage guardrails

Scripts/audit_repo_storage.sh

@@ -0,0 +1,51 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+repo_root="$(git rev-parse --show-toplevel)"
+cd "$repo_root"
+
+echo "Agrarian repository storage audit"
+echo "Repository: $repo_root"
+echo
+
+echo "Working tree size:"
+du -sh . 2>/dev/null || true
+echo
+
+echo "Git object database:"
+git count-objects -vH
+echo
+
+echo "Largest tracked files in HEAD:"
+largest_tracked="$(mktemp)"
+git ls-tree -r -l HEAD | sort -k4 -nr > "$largest_tracked"
+head -n 25 "$largest_tracked" | awk '{ printf "%10s  %s\n", $4, $5 }'
+rm -f "$largest_tracked"
+echo
+
+if git lfs version >/dev/null 2>&1; then
+  echo "Largest Git LFS objects:"
+  largest_lfs="$(mktemp)"
+  git lfs ls-files -s | sed -E 's/^.*\\(([^)]*)\\)$/\\1 &/' | sort -hr > "$largest_lfs"
+  head -n 25 "$largest_lfs"
+  rm -f "$largest_lfs"
+else
+  echo "Git LFS is not installed."
+fi
+echo
+
+echo "Generated/local directories:"
+for path in Binaries Intermediate Saved DerivedDataCache .vs Builds; do
+  if [ -e "$path" ]; then
+    du -sh "$path" 2>/dev/null || true
+  fi
+done
+echo
+
+cat <<'NOTE'
+Policy reminder:
+- Do not store packaged builds, raw DEM/lidar/GIS datasets, DerivedDataCache, or
+  generated terrain tile caches in GitHub.
+- Use Git for source, scripts, metadata, docs, and curated project assets.
+- Use DevBox or future object storage for large artifacts and source data.
+NOTE