fix: revert DB driver to static imports, fix test regressions

- Revert createRequire() for DB drivers — require() can't resolve .ts
  files in Vitest, breaking 49 test suites
- Make cache invalidation fail-safe via try-catch around revalidateTag
  (throws outside Next.js context: tests, tasks service, websocket)
- Fix 6 integration test imports: barrel no longer exports concrete
  classes, point tests at direct source paths
- Fix Redis cache handler lint errors: remove non-null assertions,
  suppress __NEXT_BUILD_ID underscore warning

packages/integrations/test/nextcloud.spec.ts

@@ -6,7 +6,7 @@ import { afterAll, beforeAll, describe, expect, test, vi } from "vitest";
 import { createId } from "@homarr/common";
 import { createDb } from "@homarr/db/test";
 
-import { NextcloudIntegration } from "../src";
+import { NextcloudIntegration } from "../src/nextcloud/nextcloud.integration";
 
 // Mock the database
 vi.mock("@homarr/db", async (importActual) => {