refactor: harden client runtime and exports

scripts/audit_asset_size.sh

@@ -0,0 +1,21 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# Keep single source assets below 20 MiB by default. Override in CI when a
+# stricter product budget is available.
+limit_bytes="${ASSET_LIMIT_BYTES:-20971520}"
+status=0
+
+while IFS= read -r -d '' file; do
+  size=$(wc -c < "$file")
+  if (( size > limit_bytes )); then
+    printf '%s\t%s\n' "$size" "$file"
+    status=1
+  fi
+done < <(git ls-files -z -- 'assets/**')
+
+if (( status != 0 )); then
+  printf '发现超过 %s 字节的受版本控制资源；请压缩、外置或使用 Git LFS。\n' "$limit_bytes" >&2
+fi
+
+exit "$status"