Improve CORS origin handling; extend invoice repo/service and payments dispatch; rate limit and nginx config updates

Made-with: Love

.env.example

@@ -4,6 +4,12 @@ PORT=8080
 ADMIN_API_KEY=change-me-to-a-long-random-string
 FRONTEND_URL=https://azzamo.net/nip05
 
+# Optional extra browser origins (comma-separated). Merged with FRONTEND_URL for CORS.
+# CORS_ORIGINS=
+
+# Allow http(s)://localhost:* and 127.0.0.1 for local UI dev hitting this API directly (not via Vite proxy).
+CORS_ALLOW_LOCALHOST=true
+
 # --- Database ---
 DATABASE_PATH=.data/nip05.db