feat: light/dark variant icons and selfh.st tag as default category

- code refactor
- reduce memory usage

internal/api/v1/favicon/favicon.go

@@ -57,7 +57,7 @@ func GetFavIcon(w http.ResponseWriter, req *http.Request) {
 	hp := r.HomepageItem()
 	if hp.Icon != nil {
 		if hp.Icon.IconSource == homepage.IconSourceRelative {
-			result = homepage.FindIcon(req.Context(), r, hp.Icon.Value)
+			result = homepage.FindIcon(req.Context(), r, *hp.Icon.FullURL)
 		} else {
 			result = homepage.FetchFavIconFromURL(req.Context(), hp.Icon)
 		}

internal/api/v1/list.go

@@ -72,9 +72,6 @@ func List(cfg config.ConfigInstance, w http.ResponseWriter, r *http.Request) {
 			gphttp.ClientError(w, err)
 			return
 		}
-		if icons == nil {
-			icons = []string{}
-		}
 		gphttp.RespondJSON(w, r, icons)
 	case ListTasks:
 		gphttp.RespondJSON(w, r, task.DebugTaskList())