feat: add Swagger UI docs, custom CORS middleware, and request logging

- Add Swagger UI files and updated API spec for Family Safety Tracker
- Replace shelf_cors_headers with custom CORS middleware in server.dart
- Add request_logger middleware with timing for auth and geo routes
- Add REGISTRATION_SECRET_KEY to .env for registration validation
- Remove postgres port exposure from docker-compose.yml
- Update opencode.json model configuration
- Add crypto dependency and update Flutter web assets

web/swagger/swagger-initializer.js

@@ -0,0 +1,19 @@
+window.onload = function() {
+  //<editor-fold desc="Changeable Configuration Block">
+
+  // the following lines will be replaced by docker/configurator, when it runs in a docker-container
+  window.ui = SwaggerUIBundle({
+    url: "/swagger/swagger.yaml",
+    dom_id: '#swagger-ui',
+    deepLinking: false,
+    presets: [
+      SwaggerUIBundle.presets.apis
+    ],
+    plugins: [
+      SwaggerUIBundle.plugins.DownloadUrl
+    ],
+    layout: "BaseLayout"
+  });
+
+  //</editor-fold>
+};