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

backups/2026-07-12-1023/landvex-prod/guides/index.html

@@ -344,7 +344,7 @@
         <div class="footer-logo">Landvex</div>
         <div class="footer-copy">© 2026 Landvex Inc · Landvex AB (org.nr 559141-7042)</div>
         <div class="footer-tagline">Decision intelligence for the physical world.</div>
-        <div style="font-size:11px;color:var(--text-muted,#888);margin-top:8px;line-height:1.6">Landvex AB · Org.nr 559141-7042<br>Tyresö, Sweden · <a href="mailto:contact@landvex.com" style="color:inherit">contact@landvex.com</a></div>
+        <div style="font-size:11px;color:var(--text-muted,#888);margin-top:8px;line-height:1.6">Landvex AB · Org.nr 559141-7042<br>Stockholm, Sweden · <a href="mailto:contact@landvex.com" style="color:inherit">contact@landvex.com</a></div>
       </div>
       <div class="footer-links">
         <a href="/privacy/">Privacy</a>