feat: finalize Better Auth migration with schema and cleanup

- Update Convex schema to work with Better Auth user structure
- Remove deprecated feedback functionality and middleware
- Update hooks and pages to use new auth patterns
- Regenerate Convex API types for Better Auth integration
- Update HTTP handlers and instrumentation for new auth system
- Update README documentation for Better Auth setup

This completes the migration from Convex Auth to Better Auth,
removing deprecated code and ensuring consistency across the application.

Author: ajanraj

README.md

@@ -195,13 +195,13 @@ Configure the required and optional Convex environment variables for your applic
 
 #### A. Authentication (Required)
 
-OS Chat uses Convex Auth for authentication with Google OAuth.
+OS Chat uses Better Auth for authentication with Google OAuth.
 
-1. **Initialize Convex Auth:**
+1. **Configure Better Auth:**
 
    ```bash
-   # Initialize Convex Auth setup
-   bunx @convex-dev/auth
+   # Better Auth is already configured in the codebase
+   # Set up your Google OAuth credentials in the Convex dashboard
    ```
 
 2. **Set up Google OAuth:**
@@ -274,7 +274,7 @@ bunx convex env set POLAR_WEBHOOK_SECRET your-polar-webhook-secret
 
 **Reference Documentation:**
 
-- [Convex Auth Setup Guide](https://labs.convex.dev/auth/setup)
+- [Convex Better Auth Documentation](https://convex-better-auth.netlify.app/)
 - [Google OAuth Configuration](https://labs.convex.dev/auth/config/oauth/google)
 - [Cloudflare R2 Component](https://www.convex.dev/components/cloudflare-r2)
 - [Polar Component Documentation](https://www.convex.dev/components/polar)
@@ -336,7 +336,7 @@ For production deployment:
 
 - Verify OAuth credentials in Convex dashboard
 - Check `SITE_URL` matches your development/production URL
-- Ensure Convex Auth is properly configured
+- Ensure Better Auth is properly configured
 
 **API Key Issues**:
 
@@ -353,7 +353,7 @@ For production deployment:
 **Need Help?**
 
 - Check the [Convex Documentation](https://docs.convex.dev)
-- Review the [Convex Auth Setup Guide](https://labs.convex.dev/auth/setup)
+- Review the [Convex Better Auth Documentation](https://convex-better-auth.netlify.app/)
 - See [Google OAuth Configuration](https://labs.convex.dev/auth/config/oauth/google) for authentication
 - Configure [Cloudflare R2](https://www.convex.dev/components/cloudflare-r2) for file storage
 - Get an [Exa API key](https://exa.ai/) for web search functionality

app/c/[chatId]/page.tsx

@@ -1,8 +1,8 @@
-import { convexAuthNextjsToken } from "@convex-dev/auth/nextjs/server";
 import { fetchQuery } from "convex/nextjs";
 import { redirect } from "next/navigation";
 import { api } from "@/convex/_generated/api";
 import type { Id } from "@/convex/_generated/dataModel";
+import { getToken } from "@/lib/auth-server";
 
 import Chat from "../../components/chat/chat";
 
@@ -12,7 +12,7 @@ export default async function ChatPage({
   params: Promise<{ chatId: string }>;
 }) {
   // Validate the chat on the server to avoid client-side flashes.
-  const token = await convexAuthNextjsToken();
+  const token = await getToken();
 
   // If we fail to obtain a token (anonymous visitor with cookies disabled, etc.)
   // we still attempt the query – Convex will treat it as anonymous and only

app/hooks/use-model-preferences.ts

@@ -24,7 +24,7 @@ export function useModelPreferences() {
     }
 
     const newFavorites = isFavorite
-      ? favorites.filter((id) => id !== modelId)
+      ? favorites.filter((id: string) => id !== modelId)
       : [...favorites, modelId];
 
     localStore.setQuery(
@@ -50,7 +50,7 @@ export function useModelPreferences() {
 
     // Remove favorite models from disabled list (auto-enable favorites)
     const newDisabled = currentDisabled.filter(
-      (id) => !newFavorites.includes(id)
+      (id: string) => !newFavorites.includes(id)
     );
 
     localStore.setQuery(

app/hooks/use-model-settings.ts

@@ -27,7 +27,7 @@ export function useModelSettings() {
 
     if (enabled) {
       // Enabling model - remove from disabled list
-      newDisabled = currentDisabled.filter((id) => id !== modelId);
+      newDisabled = currentDisabled.filter((id: string) => id !== modelId);
     } else {
       // Disabling model - add to disabled list and remove from favorites
       if (modelId === MODEL_DEFAULT) {
@@ -37,13 +37,13 @@ export function useModelSettings() {
       newDisabled = currentDisabled.includes(modelId)
         ? currentDisabled
         : [...currentDisabled, modelId];
-      newFavorites = currentFavorites.filter((id) => id !== modelId);
+      newFavorites = currentFavorites.filter((id: string) => id !== modelId);
 
       // Ensure at least one favorite remains
       if (newFavorites.length === 0 && currentFavorites.length > 0) {
         const firstFavorite = currentFavorites[0];
         newFavorites = [firstFavorite];
-        newDisabled = newDisabled.filter((id) => id !== firstFavorite);
+        newDisabled = newDisabled.filter((id: string) => id !== firstFavorite);
       }
     }
 
@@ -70,11 +70,13 @@ export function useModelSettings() {
     const currentDisabled = currentUser.disabledModels ?? [];
 
     // Filter out MODEL_DEFAULT from the models to disable
-    const modelsToDisable = modelIds.filter((id) => id !== MODEL_DEFAULT);
+    const modelsToDisable = modelIds.filter(
+      (id: string) => id !== MODEL_DEFAULT
+    );
 
     // Remove disabled models from favorites
     let newFavorites = currentFavorites.filter(
-      (id) => !modelsToDisable.includes(id)
+      (id: string) => !modelsToDisable.includes(id)
     );
     // Merge with existing disabled models
     let newDisabled = [...new Set([...currentDisabled, ...modelsToDisable])];
@@ -83,7 +85,7 @@ export function useModelSettings() {
     if (newFavorites.length === 0 && currentFavorites.length > 0) {
       const firstFavorite = currentFavorites[0];
       newFavorites = [firstFavorite];
-      newDisabled = newDisabled.filter((id) => id !== firstFavorite);
+      newDisabled = newDisabled.filter((id: string) => id !== firstFavorite);
     }
 
     localStore.setQuery(

app/privacy/page.tsx

@@ -127,7 +127,7 @@ export default function PrivacyPage() {
               responses
             </li>
             <li>
-              <strong>Authentication:</strong> Convex Auth for secure login
+              <strong>Authentication:</strong> Better Auth for secure login
             </li>
             <li>
               <strong>Payments:</strong> Polar for subscription billing

app/security/page.tsx

@@ -48,7 +48,7 @@ export default function SecurityPage() {
             <strong>Access Controls:</strong>
           </p>
           <ul>
-            <li>Authentication via Google OAuth through Convex Auth</li>
+            <li>Authentication via Google OAuth through Better Auth</li>
             <li>Users can only access their own data</li>
             <li>Server-side validation for all data access requests</li>
             <li>