Add PostGIS compose service and update public integration docs.

Wire API services to PostGIS in docker-compose, broaden CORS handling for cross-origin clients, and align developer docs with the production momswap URL.

Made-with: Cursor

docs/typescript-frontend-integration.md

@@ -2,6 +2,10 @@
 
 This document explains how frontend developers should integrate with the backend through the reusable TypeScript client at `libs/geo-api-client`.
 
+Primary backend URL for integration:
+
+- `https://momswap.produktor.duckdns.org/`
+
 ## Goals
 
 - Keep cryptographic signing logic in one place.
@@ -68,7 +72,7 @@ const storageLike = {
   removeItem: (key: string) => storage.removeItem(key),
 };
 
-const client = new GeoApiClient("http://localhost:8080", storageLike);
+const client = new GeoApiClient("https://momswap.produktor.duckdns.org", storageLike);
 
 const keys = await client.ensureKeysInStorage();
 await client.loginWithSignature(keys.publicKey, keys.privateKey);
@@ -97,3 +101,5 @@ For no-bundler apps, import the built ESM file:
 ```
 
 The backend itself serves static UI at `/web/`, but this library can be consumed by any frontend runtime that supports `fetch`, `TextEncoder`, and ES modules.
+
+For local development you can switch the client base URL to `http://localhost:8080`.