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/thread-stream/test/to-file-on-final.js

@@ -0,0 +1,24 @@
+'use strict'
+
+const fs = require('fs')
+const { Writable } = require('stream')
+
+function run (opts) {
+  let data = ''
+  return new Writable({
+    autoDestroy: true,
+    write (chunk, enc, cb) {
+      data += chunk.toString()
+      cb()
+    },
+    final (cb) {
+      setTimeout(function () {
+        fs.writeFile(opts.dest, data, function (err) {
+          cb(err)
+        })
+      }, 100)
+    }
+  })
+}
+
+module.exports = run