feat: optimize interface and database connection

Adjust MongoDB mock connector and update database structure.
Enhance sidebar, data platform, and AI analysis tools.
Clean up unnecessary code and update development docs.

#VERCEL_SKIP

Co-authored-by: null <4804959+fnvtk@users.noreply.github.com>

app/user-pool/loading.tsx

@@ -0,0 +1,22 @@
+export default function Loading() {
+  return (
+    <div className="container mx-auto py-6 space-y-6">
+      <div className="animate-pulse">
+        <div className="h-8 bg-gray-200 rounded w-1/4 mb-2"></div>
+        <div className="h-4 bg-gray-200 rounded w-1/2"></div>
+      </div>
+
+      <div className="grid grid-cols-1 md:grid-cols-5 gap-4">
+        {[...Array(5)].map((_, i) => (
+          <div key={i} className="animate-pulse">
+            <div className="h-20 bg-gray-200 rounded"></div>
+          </div>
+        ))}
+      </div>
+
+      <div className="animate-pulse">
+        <div className="h-64 bg-gray-200 rounded"></div>
+      </div>
+    </div>
+  )
+}