refactor: remove deprecated navidrome/audiobookshelf widgets

Consolidate into the unified Audio Stats widget which adapts its UI
based on the linked integration kind — Navidrome shows artists/albums/
songs/now-playing, Audiobookshelf shows libraries/audiobooks/podcasts/
listening-time/sessions.

Removes: widget definitions, components, API routers, and the
deprecatedWidgetKinds mechanism (no longer needed).

packages/api/src/router/widgets/audiobookshelf.ts

@@ -1,12 +0,0 @@
-import { audiobookshelfRequestHandler } from "@homarr/request-handler/audiobookshelf";
-
-import { createOneIntegrationMiddleware } from "../../middlewares/integration";
-import { createTRPCRouter, publicProcedure } from "../../trpc";
-
-export const audiobookshelfRouter = createTRPCRouter({
-  getStats: publicProcedure.concat(createOneIntegrationMiddleware("query", "audiobookshelf")).query(async ({ ctx }) => {
-    const innerHandler = audiobookshelfRequestHandler.handler(ctx.integration, {});
-    const data = await innerHandler.getCachedOrUpdatedDataAsync({ forceUpdate: false });
-    return data.data;
-  }),
-});

packages/api/src/router/widgets/index.ts

@@ -33,8 +33,6 @@ export const widgetRouter = createTRPCRouter({
   speedtestTracker: lazy(() => import("./speedtest-tracker").then((mod) => mod.speedtestTrackerRouter)),
   uptimeKuma: lazy(() => import("./uptime-kuma").then((mod) => mod.uptimeKumaRouter)),
   audioStats: lazy(() => import("./audio-stats").then((mod) => mod.audioStatsRouter)),
-  audiobookshelf: lazy(() => import("./audiobookshelf").then((mod) => mod.audiobookshelfRouter)),
-  navidrome: lazy(() => import("./navidrome").then((mod) => mod.navidromeRouter)),
   umami: lazy(() => import("./umami").then((mod) => mod.umamiRouter)),
   ups: lazy(() => import("./ups").then((mod) => mod.upsRouter)),
 });

packages/api/src/router/widgets/navidrome.ts

@@ -1,21 +0,0 @@
-import { z } from "zod/v4";
-
-import { navidromeRequestHandler } from "@homarr/request-handler/navidrome";
-
-import { createOneIntegrationMiddleware } from "../../middlewares/integration";
-import { createTRPCRouter, publicProcedure } from "../../trpc";
-
-export const navidromeRouter = createTRPCRouter({
-  getStats: publicProcedure
-    .concat(createOneIntegrationMiddleware("query", "navidrome"))
-    .input(
-      z.object({
-        integrationId: z.string(),
-      }),
-    )
-    .query(async ({ ctx }) => {
-      const innerHandler = navidromeRequestHandler.handler(ctx.integration, {});
-      const data = await innerHandler.getCachedOrUpdatedDataAsync({ forceUpdate: false });
-      return data.data;
-    }),
-});