Loader (cms-client.js), submodule-aware editor source path, build:watch

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

src/loader.ts

@@ -0,0 +1,8 @@
+import { runLoader } from './loader-core'
+
+runLoader({
+  location,
+  cookie: { get: () => document.cookie, set: (v) => void (document.cookie = v) },
+  scriptSrc: (document.currentScript as HTMLScriptElement | null)?.src,
+  load: (url) => import(/* @vite-ignore */ url),
+})