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

landvex-all/subprocessors/index.html

@@ -121,7 +121,7 @@
     <p>For the full DPA, see <a href="/dpa/">landvex.com/dpa/</a>.</p>
   </main>
   <footer class="lv-footer" role="contentinfo">
-    <p>© 2026 Landvex AB · Org.nr 559141-7042 · Tyresö, Sweden · <a href="/privacy/">Privacy</a> · <a href="/terms/">Terms</a> · <a href="/subprocessors/">Sub-processors</a> · <a href="/dpa/">DPA</a></p>
+    <p>© 2026 Landvex AB · Org.nr 559141-7042 · Stockholm, Sweden · <a href="/privacy/">Privacy</a> · <a href="/terms/">Terms</a> · <a href="/subprocessors/">Sub-processors</a> · <a href="/dpa/">DPA</a></p>
   </footer>
 </body>
 </html>