fix(homepage): replace GitLab links with self-hosted Gitea

Migrated from gitlab.smoothcloud.de to git.rechberg.online; drop the
now-obsolete bookmark and repoint the Services tile.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01QD5x9KR8cM7EPPsxKATHfQ

modules/environments/homepage/bookmarks.nix

@@ -1,16 +1,4 @@
 [
-  {
-    Developer = [
-      {
-        Github = [
-          {
-            abbr = "GitLab - Smoothcloud";
-            href = "https://gitlab.smoothcloud.de/";
-          }
-        ];
-      }
-    ];
-  }
   {
     Social = [
       {

modules/environments/homepage/manual-services.nix

@@ -17,10 +17,10 @@
         };
       }
       {
-        "GitLab" = {
-          href = "https://gitlab.smoothcloud.de";
-          description = "Selfhosted GitLab";
-          icon = "gitlab.png";
+        "Gitea" = {
+          href = "https://git.rechberg.online";
+          description = "Selfhosted Gitea";
+          icon = "gitea.png";
         };
       }
       {