dev-api: add developer portal, OpenAPI spec, and Flatenbadet case study

- New /developers/ page with API docs, SDKs, pricing, use cases
- OpenAPI 3.0 spec for Orders, Missions, Photos, Analytics
- Case study: Glasskiosken i Flatenbadet — complete ROI analysis
- Updated /order/ with recurring missions and frequency dropdown

services/frilans-payout/node_modules/hasown/index.js

@@ -0,0 +1,8 @@
+'use strict';
+
+var call = Function.prototype.call;
+var $hasOwn = Object.prototype.hasOwnProperty;
+var bind = require('function-bind');
+
+/** @type {import('.')} */
+module.exports = bind.call(call, $hasOwn);