feat: Implement authentication integration

src/lib/submissionItemsService.ts

@@ -154,6 +154,10 @@ export async function approveSubmissionItems(
   items: SubmissionItemWithDeps[],
   userId: string
 ): Promise<void> {
+  if (!userId) {
+    throw new Error('User authentication required to approve items');
+  }
+
   // Sort by dependency order (parents first)
   const sortedItems = topologicalSort(items);
   
@@ -285,6 +289,10 @@ export async function escalateSubmission(
   reason: string,
   userId: string
 ): Promise<void> {
+  if (!userId) {
+    throw new Error('User authentication required to escalate submission');
+  }
+
   const { error } = await supabase
     .from('content_submissions')
     .update({