manatee: Add services homepage with auto-discovery

Add a homepage module that generates a static landing page served on
port 9999 via nginx. Each service module registers itself via the shared
mod.homepage.services option, so enabling a module automatically adds
it to the page.

hosts/manatee/modules/komga/default.nix

@@ -19,6 +19,19 @@ in
   imports = [ inputs.komga-comictracker.nixosModules.default ];
 
   config = lib.mkIf enabled {
+    mod.homepage.services = [
+      {
+        name = "Komga";
+        port = 8002;
+        description = "Comic library";
+      }
+      {
+        name = "Komga Reader";
+        port = 8888;
+        description = "Comic reader";
+      }
+    ];
+
     users.users.komga = {
       isSystemUser = true;
       group = "storage";