fix: remove duplicate projects from dashboard

Gitea's /api/v1/user/repos already includes all org repos the user
has access to. Fetching org repos separately added duplicates.
Removed the redundant org-repo loop from dashboard and /api/projects.
Also fixed template to use repo.owner.login instead of _org hack.

app/templates/dashboard.html

@@ -36,7 +36,7 @@
       {% for repo in repos %}
       <a href="/board/{{ repo.owner.login }}/{{ repo.name }}" class="project-card">
         <div class="project-card-header">
-          <span class="project-org">{{ repo._org or repo.owner.login }}</span>
+          <span class="project-org">{{ repo.owner.login }}</span>
           <span class="project-name">{{ repo.name }}</span>
           {% if repo.archived %}<span class="badge archived">archivé</span>{% endif %}
           {% if repo.private %}<span class="badge private">privé</span>{% endif %}