refactor: remove unnecessary DOMContentLoaded wrappers

Since main.js has 'defer' attribute, the DOM is guaranteed to be
ready when modules execute. These wrappers are unnecessary.

dashboard.ts:
- Removed DOMContentLoaded wrapper, code runs directly
- Event delegation setup runs immediately

custom-section-builder.ts:
- Removed DOMContentLoaded wrapper
- initCustomSectionBuilder() called directly

toast.ts:
- Removed DOMContentLoaded wrapper
- initializeToastSystem() called directly at top level
- Removed dead Alpine.data registration (unused)

search.ts:
- Removed DOMContentLoaded wrapper
- initializeSearch exported for use in header

theme.ts:
- Removed DOMContentLoaded wrapper
- Functions now exported for use in header Alpine component

web/src/toast.ts

@@ -1,4 +1,3 @@
-import { Alpine } from "./alpine";
 // Toast notification system for backend errors
 // Displays toast notifications at the top of the page
 
@@ -216,24 +215,7 @@ const initializeToastSystem = (): void => {
   setupFetchInterceptor();
 };
 
-// Auto-initialize when DOM is ready
-if (typeof document !== "undefined") {
-  if (document.readyState === "loading") {
-    document.addEventListener("DOMContentLoaded", initializeToastSystem);
-  } else {
-    initializeToastSystem();
-  }
-}
-
-// Export toast API for manual use
-Alpine.data("showToast", () => ({
-  error: (message: string, duration?: number) =>
-    showToast(message, "error", duration),
-  success: (message: string, duration?: number) =>
-    showToast(message, "success", duration),
-  info: (message: string, duration?: number) =>
-    showToast(message, "info", duration),
-}));
+initializeToastSystem();
 
 export { showToast };
 export type { ToastType };