refactor(design): one drawn check for every checkable row that cannot be an input (E28 S3e3b)

ui/MenuCheck: a box filled with the accent for a set (a minus for a group
only partly in), a bare tick for one choice, in the row's leading slot.
Replaces seven hand-drawn marks: three box sizes, a tinted box, a cross
for "on" in the table filter, a trailing tick in the language menu.

frontend/src/components/PlexCollectionEditor.tsx

@@ -2,7 +2,8 @@ import { useMemo, useState } from "react";
 import { qk } from "../lib/queryKeys";
 import { useTranslation } from "react-i18next";
 import { useQuery, useQueryClient } from "@tanstack/react-query";
-import { Check, Plus } from "lucide-react";
+import { Plus } from "lucide-react";
+import { MenuCheck } from "./ui/MenuCheck";
 import { api } from "../lib/api";
 import { notifyActionError } from "../lib/actionErrors";
 import { useScrollFade } from "../lib/useScrollFade";
@@ -202,13 +203,7 @@ export default function PlexCollectionEditor({
                     inIt ? "text-accent" : ""
                   }`}
                 >
-                  <span
-                    className={`grid h-5 w-5 shrink-0 place-items-center rounded border ${
-                      inIt ? "border-accent bg-accent/20" : "border-border"
-                    }`}
-                  >
-                    {inIt && <Check className="h-3.5 w-3.5" />}
-                  </span>
+                  <MenuCheck kind="many" on={inIt} />
                   <span className="truncate">{c.title}</span>
                   <span className="shrink-0 text-xs text-muted">
                     {t("plex.collEditor.count", { count: c.child_count ?? 0 })}