🔑 refactor: MCP Settings Rendering Logic for OAuth Servers (#8718)

* feat: add OAuth servers to conditional rendering logic for MCPPanel in SideNav

* feat: add startup flag check to conditional rendering logic

* fix: correct improper handling of failure state in reinitialize endpoint

* fix: change MCP config components to better handle servers without customUserVars

- removes the subtle reinitialize button from config components of servers without customUserVars or OAuth
- adds a placeholder message for components where servers have no customUserVars configured

* style: swap CustomUserVarsSection and ServerInitializationSection positions

* style: fix coloring for light mode and align more with existing design patterns

* chore: remove extraneous comments

* chore: reorder imports and `isEnabled` from api package

---------

Co-authored-by: Danny Avila <danny@librechat.ai>

client/src/components/MCP/CustomUserVarsSection.tsx

@@ -110,13 +110,15 @@ export default function CustomUserVarsSection({
 
   const handleRevokeClick = () => {
     onRevoke();
-    // Reset form after revoke
     reset();
   };
 
-  // Don't render if no fields to configure
   if (!fields || Object.keys(fields).length === 0) {
-    return null;
+    return (
+      <div className="p-4 text-center text-sm text-gray-500">
+        {localize('com_sidepanel_mcp_no_custom_vars', { '0': serverName })}
+      </div>
+    );
   }
 
   return (