feat: initialize codex client and manage loading state in App component

This commit enhances the App component by introducing a codex client initialization process using an asynchronous function. It manages the loading state with a new `initialized` state variable, displaying a loading message while the client initializes. The store subscriptions are now set up only after successful initialization, improving the application's startup sequence and user experience.

Author: milisp

src/App.tsx

@@ -1,17 +1,40 @@
-import { useEffect } from "react";
+import { useEffect, useState } from "react";
 import { Layout } from "@/components/layout";
 import { useDeepLink } from "./hooks/useDeepLink";
 import { initializeActiveConversationSubscription } from "@/stores/codex/useActiveConversationStore";
+import { invoke } from "@/lib/tauri-proxy";
+import { InitializeResponse } from "@/bindings/InitializeResponse";
 import "./App.css";
 
 export default function App() {
   // Initialize deep linking - must be called at top level, not conditionally
   useDeepLink();
+  const [initialized, setInitialized] = useState(false);
 
   useEffect(() => {
-    // Initialize store subscriptions
-    initializeActiveConversationSubscription();
+    // Initialize codex client before any other operations
+    const initializeCodex = async () => {
+      try {
+        await invoke<InitializeResponse>("initialize_client");
+        console.log("Codex client initialized successfully");
+        setInitialized(true);
+      } catch (error) {
+        console.error("Failed to initialize codex client", error);
+        // Still mark as initialized to allow UI to load, but log the error
+        setInitialized(true);
+      }
+
+      // Initialize store subscriptions after codex client is initialized
+      initializeActiveConversationSubscription();
+    };
+
+    // Wait for initialization
+    initializeCodex();
   }, []);
 
+  if (!initialized) {
+    return <div className="flex items-center justify-center h-screen">Initializing...</div>;
+  }
+
   return <Layout />;
 }