feat: Centralize configuration management for Nostr and API settings

- Introduce a new config module to manage Nostr relays, admin pubkeys, and API settings.
- Update components to utilize the centralized config instead of environment variables directly.
- Refactor relevant files to improve maintainability and reduce reliance on environment variables.

src/components/events/PurchaseTicketDialog.vue

@@ -6,6 +6,7 @@ import { Button } from '@/components/ui/button'
 import { Input } from '@/components/ui/input'
 import { Label } from '@/components/ui/label'
 import QRCode from 'qrcode'
+import { config } from '@/lib/config'
 
 interface Props {
   event: {
@@ -49,14 +50,14 @@ async function handleSubmit() {
   isLoading.value = true
   error.value = ''
 
-  const apiUrl = `${import.meta.env.VITE_API_BASE_URL}/events/api/v1/tickets/${props.event.id}/${encodeURIComponent(name.value)}/${encodeURIComponent(email.value)}`
+  const apiUrl = `${config.api.baseUrl}/events/api/v1/tickets/${props.event.id}/${encodeURIComponent(name.value)}/${encodeURIComponent(email.value)}`
   console.log('Calling API:', apiUrl)
 
   try {
     const response = await fetch(apiUrl, {
       headers: {
         'Accept': 'application/json',
-        'X-API-KEY': import.meta.env.VITE_API_KEY
+        'X-API-KEY': config.api.key
       }
     })