Allow all hosts for Vite development server in Replit environment

Configure vite.config.ts to set `allowedHosts: true` and update replit.md to document this change, enabling the development server to accept requests from Replit's dynamic proxy hostnames.

Replit-Commit-Author: Agent
Replit-Commit-Session-Id: 9203795e-937a-4306-b81d-b4d5c78c240e
Replit-Commit-Checkpoint-Type: full_checkpoint
Replit-Commit-Event-Id: 67514a43-55bc-402d-96bf-6b8994c3e0fd
Replit-Commit-Screenshot-Url: https://storage.googleapis.com/screenshot-production-us-central1/7c94b7a0-29c7-4f2e-94ef-44b2153872b7/9203795e-937a-4306-b81d-b4d5c78c240e/FjR2iCp
Replit-Helium-Checkpoint-Created: true

replit.md

@@ -59,6 +59,7 @@ npm start           # Start production server
 ### Development
 - The development server runs on **port 5000** (required for Replit's webview)
 - Host is set to `0.0.0.0` to allow Replit proxy access
+- `allowedHosts: true` configured to allow Replit's dynamic proxy hostnames
 - Vite HMR is configured for proper hot reload in Replit environment
 
 ### Deployment

vite.config.ts

@@ -8,6 +8,7 @@ export default defineConfig(({ mode }) => ({
     host: "0.0.0.0",
     port: 5000,
     strictPort: true,
+    allowedHosts: true,
     hmr: {
       clientPort: 5000,
     },