chore(ci): guard local artifacts and trim placeholders

- add scripts/check_local_artifacts.sh and run it early in CI jobs

- add scripts/clean.sh for local cleanup of generated artifacts

- remove unused asset placeholder .gitkeep files

Tests: cargo test && cargo build

Author: saagar210

.github/workflows/ci.yml

@@ -13,6 +13,9 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v4
 
+      - name: Guard local artifacts
+        run: ./scripts/check_local_artifacts.sh
+
       - name: Setup Rust
         uses: dtolnay/rust-toolchain@stable
         with:
@@ -43,6 +46,9 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v4
 
+      - name: Guard local artifacts
+        run: ./scripts/check_local_artifacts.sh
+
       - name: Install Linux native build deps
         run: |
           sudo apt-get update

assets/critters/.gitkeep

@@ -0,0 +1,25 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+repo_root="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+cd "$repo_root"
+
+mapfile -t tracked_files < <(git ls-files)
+offenders=()
+
+for path in "${tracked_files[@]}"; do
+  case "$path" in
+    *.DS_Store|target/*|.codex_audit/*)
+      offenders+=("$path")
+      ;;
+  esac
+done
+
+if [ "${#offenders[@]}" -gt 0 ]; then
+  echo "Local artifact guard failed."
+  echo "Remove these tracked files before committing:"
+  printf '  - %s\n' "${offenders[@]}"
+  exit 1
+fi
+
+echo "Local artifact guard passed."

assets/fonts/.gitkeep

@@ -0,0 +1,43 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+repo_root="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+cd "$repo_root"
+
+bytes_before="$(du -sk . 2>/dev/null | awk '{print $1}')"
+
+cleaned_any=0
+
+# Remove macOS finder metadata files that can appear in project trees.
+while IFS= read -r ds_store; do
+  if find "$ds_store" -maxdepth 1 -name '.DS_Store' -print -quit | grep -q .; then
+    find "$ds_store" -maxdepth 1 -name '.DS_Store' -delete
+    cleaned_any=1
+  fi
+done < <(printf '%s\n' "$repo_root" "$(dirname "$repo_root")")
+
+# Remove generated Rust build output.
+if [ -d "target" ]; then
+  find target -depth -mindepth 1 -delete
+  rmdir target 2>/dev/null || true
+  cleaned_any=1
+fi
+
+# Remove local Codex audit scratch artifacts if present.
+if [ -d ".codex_audit" ]; then
+  find .codex_audit -depth -mindepth 1 -delete
+  rmdir .codex_audit 2>/dev/null || true
+  cleaned_any=1
+fi
+
+bytes_after="$(du -sk . 2>/dev/null | awk '{print $1}')"
+freed_kb=$((bytes_before - bytes_after))
+if [ "$freed_kb" -lt 0 ]; then
+  freed_kb=0
+fi
+
+if [ "$cleaned_any" -eq 1 ]; then
+  echo "Cleanup complete. Freed approximately ${freed_kb} KB."
+else
+  echo "Nothing to clean."
+fi